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  • fish  (211)
  • Inversion
  • Rat
  • Springer  (271)
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  • 1995-1999  (270)
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    Tortonian-Pleistocenic oceanic features in the Southern Tyrrhenian Sea: magnetic inverse model of the Selli-Vavilov region (2009)
    Springer
    Details
    Publication Date: 2017-04-04
    Description: We show the magnetic model of the Selli-Vavilov region. The Selli Line is known as the northwestern edge of the southern Tyrrhenian basin. The tectonic evolution of the Tyrrhenian basin is dominated by a Tortonian - Quaternary extension through the eastward movement of the Apennine subduction system. This migration has generated a diffuse stretching of the continental crust with the emplacement of new oceanic material. This latter occurred in several localized zones where the eastward retreating of the Ionian subduction system produced a strong depletion of the crust with formation of basins and correlated spreading. Nowadays the presence of oceanic crust is confirmed through direct drilling investigation but a complete mapping of the oceanic crustal distribution is still lacking. The Selli-Vavilov region shows a differentiated crustal setting where seamount structures, the oceanic basement portions and continental crust blocks are superimposed. To this aim, a 2D inversion of the magnetic data of this region was conducted to define buried structures. The magnetic susceptibility pattern was computed by solving the least squares problem of the misfit between the predicted and real data for separated wavebands. This method produced two 2D models of the high and low frequency fields of the Selli-Vavilov region. The two apparent susceptibility maps provide different information for distinct ranges of depth. The results of the inversions were also combined with seismic data of the Selli region highlighting the position of the highly-magnetized buried bodies. The results confirm a role for the Selli Line as a deep crustal boundary dividing the Sardinian passive domain from the easternmost active region where different oceanic structures are located. The Selli Line has worked as a detachment fault system which has moved eastward. Finally, the Selli-Vavilov region may be interpreted as a tectonic result due to a passive asymmetrical rift occurred between the Tortonian and Pliocene.
    Description: Published
    Description: 251-266
    Description: 2.6. TTC - Laboratorio di gravimetria, magnetismo ed elettromagnetismo in aree attive
    Description: 3.4. Geomagnetismo
    Description: 3.5. Geologia e storia dei sistemi vulcanici
    Description: JCR Journal
    Description: reserved
    Keywords: Geomagnetism ; Tectonics ; Geodynamics ; Inversion ; Oceanic crust ; Volcanic structure ; 04. Solid Earth::04.05. Geomagnetism::04.05.04. Magnetic anomalies ; 04. Solid Earth::04.07. Tectonophysics::04.07.02. Geodynamics ; 05. General::05.01. Computational geophysics::05.01.03. Inverse methods
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
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  • 2
    Electronic Resource
    Electronic Resource
    Is the inversion effect in rhesus monkeys face-specific? (1999)
    Springer
    Animal cognition 2 (1999), S. 123-129 
    Details
    ISSN: 1435-9456
    Keywords: Key words Face recognition ; Inversion ; Expertise ¶effect ; Matching-to-sample ;  Macaca mulatta
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract This study investigated the face inversion effect in rhesus monkeys (Macaca mulatta). Face stimuli consisted of ten black-and-white examples of unfamiliar rhesus monkey faces, brown capuchin faces, and human faces. Two non-face categories included ten examples of automobiles and abstract shapes. All stimuli were presented in a sequential matching-to-sample format using an automated joystick-testing paradigm. Subjects performed significantly better on upright than on inverted presentations of automobiles, rhesus monkey and capuchin faces, but not human faces or abstract shapes. These results are inconsistent with data from humans and chimpanzees that show the inversion effect only for categories of stimuli for which subjects have developed expertise. The inversion effect in rhesus monkeys does not appear to be face-specific, and should therefore not be used as a marker of specialized face processing in this species.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s100710050032
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  • 3
    Electronic Resource
    Electronic Resource
    Nucleotide sequences of three distinct complementary DNA clones encoding rat class II major histocompatibility complex RT1.D β-chain proteins (1999)
    Springer
    Immunogenetics 49 (1999), S. 735-737 
    Details
    ISSN: 1432-1211
    Keywords: Key words Class II MHC sequence ; Rat ; Cloning ; RT-PCR ; Polymorphism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002510050676
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  • 4
    Electronic Resource
    Electronic Resource
    Differential Scanning Calorimetric Investigations on Pyloric Caeca During Ripening of Salted Herring Products (1999)
    Springer
    Journal of thermal analysis and calorimetry 57 (1999), S. 283-291 
    Details
    ISSN: 1572-8943
    Keywords: DSC ; fish ; general proteolytic activity ; pyloric caeca ; ripening ; salted herring product
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The thermoanalytical behaviour of pyloric caeca during salting and ripening was investigated using a Perkin Elmer DSC 7. Not only the thermal stability of the muscle proteins was influenced by salting but also that of pyloric caeca. It was recognised that the salting itself leads to a remarkable increase of the transition temperature compared with raw herring. An influence of the salt:fish ratio could be observed. The higher the salt content the higher the increase of the denaturation temperature. During ripening the transition temperature remained on a high level or showed only a slight decrease during the investigation period. The dependency from the salt content remained evident. The increase of the transition temperature was accompanied by a decrease of the transition enthalpy. The increase of thermal stability is connected with a decrease of the general proteolytic activity in pyloric caeca. Possibly, the enzymes are diffusing from the pyloric caeca into the muscle and cause there an increase of enzymatic activity observable in North Sea herring accompanied by a decrease of activity in pyloric caeca itself. Simultaneous the thermal stability of pyloric caeca is lowered. The reason for the differences in ripening could be seen in some enzyme-inhibiting factors unknown until now.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1010101910394
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  • 5
    Electronic Resource
    Electronic Resource
    Uptake of Copper by Neon Tetras (Paracheirodon innesi) in the Presence and Absence of Particulate and Humic Matter (1999)
    Springer
    Ecotoxicology 8 (1999), S. 269-275 
    Details
    ISSN: 1573-3017
    Keywords: fish ; speciation ; copper ; bioavailability ; bioaccumulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Neon tetras Paracheirodon innesi were exposed to various species of copper during exposures to evaluate the bioavailability of free copper (0 to 2 mg/l), copper apparently complexed to humic substances (0 to 160 mg/l), and copper adsorbed on kaolin clays (0 to 182 mg/l). The results of the experiments demonstrated that free copper is the most bioavailable form. Both humic substances and kaolin clay particulates reduced copper bioavailability to the fish. However, fish accumulated a fraction of copper complexed to humic substances and part of copper adsorbed on kaolin clays.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008977131711
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  • 6
    Electronic Resource
    Electronic Resource
    Cytokine-induced conversion of mesencephalic-derived progenitor cells into dopamine neurons (1999)
    Springer
    Cell & tissue research 296 (1999), S. 235-246 
    Details
    ISSN: 1432-0878
    Keywords: Key words Transplantation ; Parkinson’s disease ; CNS fetal development ; CNS differentiation ; Neurotrophic factors ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract We have previously shown that a combination of the cytokines interleukin (IL)-1, IL-11, leukemia inhibitory factor (LIF), and glial cell line-derived neurotrophic factor (GDNF) can convert rat fetal (E14.5) mesencephalic progenitor cells into tyrosine hydroxylase (TH)-immunoreactive (ir) neurons in vitro. The experiments described here characterize the mesencephalic progenitor cells and their cytokine-induced conversion into dopamine (DA) neurons. For all experiments, we used bromodeoxyuridine (BrdU)-ir cultures of (E14.5) mesencephalic progenitor cells that had been expanded at least 21 days. We first demonstrated that IL-1 induced DA neuron conversion in mesencephalic progenitors, but not in striatal progenitors (P〈0.001). Thus, these cells should be classified as lineage-restricted progenitors, and not omnipotent stem cells. To further characterize cell populations in these cultures, we used monoclonal antibodies against Hu (an early marker for neurons), growth-associated protein (GAP)-43 (a marker for neuronal process extension), TH (a marker for DA neurons), and glial fibrillary acidic protein (GFAP, a marker for astrocytes). We assessed (E14.5) mesencephalic progenitor cell cultures (plated at 125,000 cells/cm2) incubated in the cytokine mixture (described above) or in complete media (CM, negative control). Following 7 days incubation, GFAP-positive cells formed a nearly confluent carpet in both types of cultures. However, numbers of Hu-ir and GAP-43-ir cells in the cytokine-incubated cultures far exceeded those in CM-incubated controls (P=0.0003, P=0.0001, respectively), while numbers of TH-ir cells were 58-fold greater in the cytokine-incubated cultures versus CM-incubated controls. The TH phenotype persisted for 7 days following withdrawal of the differentiation media. Numerous double-labeled cells that were BrdU-ir and also TH-ir, or Hu-ir and also TH-ir, were observed in the cytokine-incubated cultures. These data suggest that cytokines ”drive” the conversion of progenitor cells into DA neurons.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410051285
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  • 7
    Electronic Resource
    Electronic Resource
    Trk-neurotrophin receptor-like immunoreactivity in the gut of teleost species (1999)
    Springer
    Cell & tissue research 296 (1999), S. 323-330 
    Details
    ISSN: 1432-0878
    Keywords: Key words Neurotrophins ; Trk receptors ; Nervous system ; Endocrine cells ; Gut ; fish ; Teleosts
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Neurotrophins, acting through their high-affinity signal-transducing Trk receptors, are involved in the development, differentiation and maintenance of discrete neuron populations in the higher vertebrates. Furthermore, the presence of Trk receptors in some non-neuronal tissues, including the endocrine cells of the gut, could indicate an involvement of neurotrophins also in these tissues. Recently, neurotrophins and neurotrophin receptor proteins have been identified in the lower vertebrates and invertebrates, whose amino acid sequences are highly homologous with those found in mammals. The present study investigates the occurrence and distribution of Trk-like proteins in the neurons and gut endocrine cells in five species of teleost. Single and double immunolabeling was carried out on fresh and paraffin-embedded tissue using commercially available antibodies against sequences of the intracytoplasmic domain of the mammalian Trk. Western-blot analysis, carried out on samples of stomach and intestine of bass, identified proteins whose estimated molecular masses (140 kDa, 145 kDa and 143–145 kDa) were similar to those reported for full-length TrkA, TrkB and TrkC in the higher vertebrates. TrkA-like immunoreactivity was found in the enteric nervous system plexuses of three fish species. Trk-like immunoreactivity was observed in the endocrine cells as follows: sparse TrkA-like immunoreactive endocrine cells were detected only in the intestine; TrkB-like immunoreactive cells were detected only in the stomach; and TrkC-like immunoreactive cells were found both in the intestine of the carp and in the stomach of the bass, where they also showed TrkB-like immunoreactivity. These findings confirm the occurrence and distribution of Trk-like proteins in teleosts. These proteins are closely related to the Trk neurotrophin receptors of mammals. The functional significance of Trk-like proteins in both neuronal and non-neuronal cells of teleosts is still not clear.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410051292
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  • 8
    Electronic Resource
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    Isograft and xenograft of the subcommissural organ into the lateral ventricle of the rat and the formation of Reissner’s fiber (1999)
    Springer
    Cell & tissue research 296 (1999), S. 457-469 
    Details
    ISSN: 1432-0878
    Keywords: Key words Subcommissural organ ; Isograft ; Xenograft ; Reissner’s fiber ; Cerebrospinal fluid ; Rat ; Bovine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  The subcommissural organ (SCO) secretes glycoproteins into the cerebrospinal fluid (CSF) that aggregate and form Reissner’s fiber (RF). The factors involved in this aggregation are not known. One factor may be the hydrodynamics of the CSF when flowing through the aqueduct. This hypothesis was tested by isografting rat SCO and xenografting bovine SCO into the lateral ventricle of rats. Xenografts were either fresh bovine SCO or explants cultured for 30 days before transplantation. The grafts were investigated by electron microscopy and immunocytochemistry using antibodies against RF glycoproteins, serotonin and the glucose transporter I. Maximal time of transplantation was 43 days for isografts and 14 days for xenografts. The isografts were not reinnervated but were revascularized; they secreted into the ventricle RF glycoproteins that became progressively packed into pre-RF and RF structures identical to those formed by the SCO in situ. RF was confined to the host ventricle and at its distal end the constituent proteins disassembled. Xenografts were neither reinnervated nor revascularized and secreted into the host ventricle a material that never formed an RF. These findings indicate that the CSF factor responsible for the formation of RF is species specific, and that this process does not depend on the hydrodynamics of the CSF. The blood vessels revascularizing the isografted SCO acquired the characteristics of the vessels irrigating the SCO in situ, namely, a tight endothelium displaying glucose transporter I, and a perivascular space containing long-spacing collagen, thus indicating that basal release of glycoproteins may also occur in the grafted SCO.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410051306
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  • 9
    Electronic Resource
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    Axonal and dendritic transport in Purkinje cells of cerebellar slice cultures studied by microinjection of horseradish peroxidase (1999)
    Springer
    Cell & tissue research 295 (1999), S. 55-64 
    Details
    ISSN: 1432-0878
    Keywords: Key words Axonal transport ; Purkinje cell ; Organotypic culture ; Microinjection ; Antimitotic drugs ; Cytoskeleton ; Dendritic transport ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Axonal and dendritic transport in single Purkinje neurons of cerebellar slice cultures was quantified as single transport distances. Examination of the cells within a vital tissue was regarded as being an approach to the in situ condition. The Purkinje cells were organotypically integrated in the in vitro tissues and extended long axonal projections connecting synapses to the target neurons. The tracer horseradish peroxidase (HRP) was applied via microinjection to the somata of the Purkinje cells and the injected neurons were incubated thereafter for defined time-intervals. The tracer was transported anterogradely into the neuron processes. The measurements on both the axonal and the dendritic transport of microinjected HRP revealed continuous transportation with increasing times of postincubation. This transport was reduced by the use of microtubule-depolymerizing drugs. The axonal transport of the tracer was either retarded in colchicine-treated cells or continuously reduced for up to 50% in vinblastine-treated neurons. Thus, a correlation of axonal transport to the microtubules was demonstrated. The dendrites were filled with the tracer after 60 min of postincubation. Dendritic transport was reduced by the use of vinblastine, and not significantly by colchicine. The results strongly support the dependence of neuronal transport on microtubules as a component of the cytoskeleton.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410051212
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  • 10
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    Cellular and subcellular distribution of the calcium-binding protein NCS-1 in the central nervous system of the rat (1999)
    Springer
    Cell & tissue research 295 (1999), S. 395-407 
    Details
    ISSN: 1432-0878
    Keywords: Key words Neurofilament ; Basket cell ; Pinceau ; Golgi apparatus ; Calcium binding protein ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract NCS-1 (neuronal calcium sensor) is a recently characterized member of a highly conserved neuron-specific family of calcium-binding proteins, which also includes frequenin and recoverin. The cellular and subcellular distributions of NCS-1 in the rat nervous system were investigated using light- and electron-microscopic immunohistochemistry. NCS-1 immunoreactivity was localized to neuronal cell bodies and axons throughout the brain and spinal cord but not to glial cells. The most intense labeling was observed in myelinated axons, the axonal ramifications of the basket cell in the cerebellar cortex, and large neurons in the brainstem and pons. These same structures were also characterized by heavy labeling for neurofilament protein, as determined by double-labeling experiments. Most axon terminals were unlabeled or only lightly labeled. The most remarkable subcellular staining occurred in the perikarya where intense labeling was associated with the membranes of the trans saccules of the Golgi apparatus. The widespread distribution of NCS-1 indicates that it may be active in a variety of calcium-dependent neuronal functions, whereas the specific subcellular localization to the Golgi apparatus and neurofilament-rich structures suggests a specialized role in calcium regulated protein trafficking and cytoskeletal interactions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410051246
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  • 11
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    Expression of neurotrophins, GDNF, and their receptors in rat thyroid tissue (1999)
    Springer
    Cell & tissue research 295 (1999), S. 467-475 
    Details
    ISSN: 1432-0878
    Keywords: Key words Glial cell line-derived neurotrophic factor ; GDNF ; Ret ; GDNFR-α ; Brain-derived neurotrophic factor ; BDNF ; NT-3 ; NT-4 ; trk receptors ; Thyroid tissue ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Levels of mRNA for neurotrophins (brain-derived neurotrophic factor, BDNF; neurotrophin 3, NT-3; neurotrophin 4, NT-4) and their receptors (trkA, trkB, trkC) and for glial cell line-derived neurotrophic factor (GDNF) and its receptors (ret, GDNFR-α) were measured in rat thyroid tissue by ribonuclease protection assays. In thyroid tissue the NT-3 mRNA level was threefold lower and the NT-4 mRNA level sixfold higher than those detected in adult rat hippocampus, while BDNF mRNA was undetectable. Very low levels of mRNA for truncated trkB and trkC receptors and no catalytic trkA, trkB or trkC were found. In conclusion NT-3 and NT-4, but not the corresponding functional receptors, are expressed in the thyroid tissue. Therefore, it is unlikely that these factors serve a direct local autocrine or paracrine function in thyroid cell types, and a target-derived mode of action on neurons innervating the thyroid tissue is suggested. An opposite result has been found for the neurotrophic factor GDNF: thyroid tissue showed a high level of transcripts for the GDNF receptor subunits (GDNFR-α and Ret), while GDNF mRNA was undetectable. The in situ hybridization analysis of GDNFR-α and ret mRNA revealed an interesting difference in the cell distribution of these transcripts: ret mRNA is selectively expressed in a subpopulation of cells scattered in the follicular epithelium and in the interfollicular spaces, while GDNFR-α expression is more homogeneous and widespread, including the more abundant cell type of the thyroid gland: the follicular cell. Double-labeling in situ hybridization/immunocytochemistry experiments, with a specific marker (calcitonin), showed that parafollicular cells express ret but not GDNFR-α. This differential distribution of the GDNF receptor components (GDNFR-α and ret) may reflect a peculiar biological role in intercellular communication in the thyroid gland.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410051252
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  • 12
    Electronic Resource
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    Aquaporin-5 (AQP5), a water channel protein, in the rat salivary and lacrimal glands: immunolocalization and effect of secretory stimulation (1999)
    Springer
    Cell & tissue research 295 (1999), S. 513-521 
    Details
    ISSN: 1432-0878
    Keywords: Key words Water channel protein ; Aquaporin ; AQP5 ; Rat ; Salivary glands ; Immunolocalization ; Secretory stimulation ; Rat (Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Aquaporin-5 (AQP5) is a water channel protein and is considered to play an important role in water movement across the plasma membrane. We raised anti-AQP5 antibody and examined the localization of AQP5 protein in rat salivary and lacrimal glands by immunofluorescence microscopy. AQP5 was found in secretory acinar cells of submandibular, parotid, and sublingual glands, where it was restricted to apical membranes including intercellular secretory canaliculi. In the submandibular gland, abundant AQP5 was also found additionally at the apical membrane of intercalated duct cells. Upon stimulation by isoproterenol, apical staining for AQP5 in parotid acinar cells tended to appear as clusters of dots. These results suggest that AQP5 is one of the candidate molecules responsible for the water movement in the salivary glands.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410051257
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  • 13
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    Changes in the Tagus nursery function for commercial fish species: some perspectives for management (1999)
    Springer
    Aquatic ecology 33 (1999), S. 287-292 
    Details
    ISSN: 1573-5125
    Keywords: community analysis ; estuary ; fish ; nursery
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The Tagus estuary has long been subjected to several human activities and uses. Changes in the estuarine fish community were evaluated based on beam trawl surveys in 1978–1980 and 1994–1996. There was a decrease of abundance of many species that use the Tagus as a nursery, namely bib (Trisopterus luscus), five bearded rockling (Ciliata mustela), tub gurnard (Trigla lucerna), and flounder (Platichthys flesus), possibly due to reduction of the water quality. In 1994–1996, only sea bass (Dicentrarchus labrax), sole (Solea solea) and Solea senegalensis Kaup, 1858, were found within the nursery grounds, showing an irregular pattern of abundance. Condition and vacuity index were highly variable. The major problems affecting the fish community, namely pollution, fishery regulation and waterflow regulation, are discussed in relation to the management and conservation of this estuarine system.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009904621771
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  • 14
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    Impact: Toward a Framework for Understanding the Ecological Effects of Invaders (1999)
    Springer
    Biological invasions 1 (1999), S. 3-19 
    Details
    ISSN: 1573-1464
    Keywords: abundance ; bioindicators ; fish ; hybridization ; impact ; invasion models ; invasional meltdown ; invasions ; models ; nonindigenous species ; range
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Although ecologists commonly talk about the impacts of nonindigenous species, little formal attention has been given to defining what we mean by impact, or connecting ecological theory with particular measures of impact. The resulting lack of generalizations regarding invasion impacts is more than an academic problem; we need to be able to distinguish invaders with minor effects from those with large effects in order to prioritize management efforts. This paper focuses on defining, evaluating, and comparing a variety of measures of impact drawn from empirical examples and theoretical reasoning. We begin by arguing that the total impact of an invader includes three fundamental dimensions: range, abundance, and the per-capita or per-biomass effect of the invader. Then we summarize previous approaches to measuring impact at different organizational levels, and suggest some new approaches. Reviewing mathematical models of impact, we argue that theoretical studies using community assembly models could act as a basis for better empirical studies and monitoring programs, as well as provide a clearer understanding of the relationship among different types of impact. We then discuss some of the particular challenges that come from the need to prioritize invasive species in a management or policy context. We end with recommendations about how the field of invasion biology might proceed in order to build a general framework for understanding and predicting impacts. In particular, we advocate studies designed to explore the correlations among different measures: Are the results of complex multivariate methods adequately captured by simple composite metrics such as species richness? How well are impacts on native populations correlated with impacts on ecosystem functions? Are there useful bioindicators for invasion impacts? To what extent does the impact of an invasive species depend on the system in which it is measured? Three approaches would provide new insights in this line of inquiry: (1) studies that measure impacts at multiple scales and multiple levels of organization, (2) studies that synthesize currently available data on different response variables, and (3) models designed to guide empirical work and explore generalities.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1010034312781
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  • 15
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    Lectin like properties and differential sugar binding characteristics of C-reactive proteins purified from sera of normal and pollutant induced Labeo rohita (1999)
    Springer
    Glycoconjugate journal 16 (1999), S. 741-750 
    Details
    ISSN: 1573-4986
    Keywords: C-reactive protein ; pollutant ; agglutinin ; galactose binding lectin ; fish ; Labeo rohita
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Different forms of C-reactive proteins (CRPs) have been purified to electrophoretic homogeneity from the sera of Labeo rohita confined in freshwater (CRPN) and water polluted with nonlethal doses of cadmium (CRPCd) or mercury (CRPHg). CRPN[emsp4 ], CRPCd[emsp4 ], and CRPHg show remarkable differences in their electrophoretic mobility but exhibit strong immunological cross reactivity. All these CRPs exhibit variable agglutination properties with erythrocytes from diverse sources in presence of Ca+2, which could be inhibited by a variety of sugars showing specificity for galactose. Inhibition results show that the potency of galactose as an inhibitor increases about 4 fold in the process of transformation of CRPN to CRPCd and CRPHg[emsp4 ]. In case of CRPN[emsp4 ], Gal β(1→1) Gal and oNO2 phenyl β-Gal show highest inhibitory potency while oNO2-phenyl β-Gal is the most potent inhibitor for CRPCd and CRPHg but the potency of Gal β(1→1) Gal reduced drastically. 6-phosphate D-Gal and stachyose are 20 times weaker inhibitors than D-Gal for induced CRP mediated agglutination, in contrast, these sugars are only 6 times weaker for CRPN[emsp4 ]. Dissociation constants of the binding of CRPN with phosphoryl choline (PC) and galactose are about 9[emsp4 ]mM and PC binding causes a change in the α and β conformations of these CRPs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1007167611778
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  • 16
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    Do fish communities function as biotic vectors of organic matter between salt marshes and marine coastal waters? (1999)
    Springer
    Aquatic ecology 33 (1999), S. 293-299 
    Details
    ISSN: 1573-5125
    Keywords: outwelling ; salt marshes ; organic matter ; transfer ; fish ; vector
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The contribution of fish communities to organic matter (OM) fluxes, especially between salt marshes and adjacent marine coastal waters are reviewed. For this a data set from the bay of Mont Saint-Michel and literature is examined and discussed. In a range of macro-tidal coasts of Europe, salt marshes are only flooded at spring tides for a short time. Many animals, including fish, then invade the salt marshes through tidal creeks. They forage there for up to a few hours and swim back to sea at ebb. Meanwhile, organic matter is exported as gut content. In the 4000 ha of salt marshes of the bay of Mont Saint-Michel mullets were responsible for the export of about 8 kg of dry weight OM ha−1 in 1996 and of roughly 12 kg in 1997. Although spatio-temporally variable, the fish communities appear to play a more or less significant role, as ‘biotic vectors’ in the nutrient fluxes between salt marshes and coastal waters.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009956605842
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  • 17
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    The bioavailability of magnesium from Wakame ( Undaria pinnatifida) and Hijiki (Hijikia fusiforme) and the effect of alginic acid on magnesium utilization of rats (1999)
    Springer
    Plant foods for human nutrition 53 (1999), S. 265-274 
    Details
    ISSN: 1573-9104
    Keywords: Bioavailability ; Magnesium ; Hijiki ; Sodium alginate ; Rat ; Wakame
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The bioavailability of magnesium from Wakame and Hijiki, and the effects of alginic acid on absorption of dietary magnesium were examined in five groups of rats fed either control, Wakame, Hijiki, AW (containing the same amount of alginate as in the Wakame) and AH (containing the same amount of alginate as in the Hijiki) diets, and animals fed a low magnesium diet (LMg) (twentieth amount of magnesium in the original mineral mixtures as the control). Food intake and body weight gain were decreased by adding sodium alginate to the diets. A large amount of calcium accumulated only in the kidneys of the rats fed the LMg diet. Serum magnesium concentration decreased only in the LMg group. The magnesium content in the defatted left femurs did not differ between the control and Wakame fed animals and also among the animals eating Wakame, Hijiki and AW diets. The breaking force of the right femurs did not differ among all the groups except the LMg group. The ratio of apparent magnesium absorption (%) of the control, LMg, Wakame, Hijiki, AW and AH groups was 82.2, 72.7, 66.9, 50.8, 69.3 and 54.2 in the first experimental period, and was 75.3, 52.1, 57.7, 46.9, 62.6 and 60.5 in the second experimental period, respectively. It was clear that the bioavailability of magnesium in the Wakame fed rats was higher than in those eating the Hijiki. Large amounts of sodium alginate lowered magnesium absorption from the diet.
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    URL: http://dx.doi.org/10.1023/A:1008082112178
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  • 18
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    Biota contamination by PCBs and trace metals in the freshwater estuary of the River Seine (France) (1999)
    Springer
    Hydrobiologia 400 (1999), S. 149-154 
    Details
    ISSN: 1573-5117
    Keywords: polychlorobiphenyls ; trace metals ; fish ; Seine estuary
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We studied the impact of urban and industrial activity upon the occurrence and the distribution of pollutants in the fresh estuary of the River Seine. Contamination was investigated under dry weather conditions, by determination of PCB and trace metal levels upstream and downstream of Rouen and the pollutant content of organisms with different positions in the trophic web. PCB contents of roach were higher downstream than upstream of Rouen. Cd levels showed a regular four fold increase from upstream to downstream of Rouen. Cyprinidae (ablet, roach) showed similar PCB or even higher trace metal levels than their predators (Percidae). This result suggests that contaminated food intake was not the main pathway for pollutant accumulation.
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    URL: http://dx.doi.org/10.1023/A:1003715131607
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  • 19
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    Fish communities and river alteration in the Seine Basin and nearby coastal streams (1999)
    Springer
    Hydrobiologia 400 (1999), S. 155-166 
    Details
    ISSN: 1573-5117
    Keywords: fish ; Index of Biotic Integrity ; water quality ; habitat diversity ; substrate clogging ; France
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Spatial variation of quality of fish communities in the whole Seine basin and nearby coastal streams were examined by the Index of Biotic Integrity (IBI). The relationship between quality of fish communities and river alteration was also studied. A trend of fish community degradation was found from the periphery to the centre of the basin and from upstream to downstream. This trend is conform with the gradient of anthropic pressures observed in the catchment. Variations in IBI scores were significantly related to water quality, diversity of physical habitat and substrate clogging. In headwaters, effects of water quality and substrate clogging were predominant, suggesting that fish community quality is first linked to land use in the catchment. Downstream, IBI scores were mainly linked with diversity of habitat suggesting that fish community quality principally depends on direct river bed alterations. Relationships between each metric of the IBI and the river features tended to show that reduction of habitat heterogeneity first reduced species richness, whereas degradation of water quality first affected the functional structure of the fish community. These results provide useful elements to develop a global rehabilitation of fish communities at the whole basin scale.
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    URL: http://dx.doi.org/10.1023/A:1003752215677
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  • 20
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    Factors affecting food consumption and growth of walleye, Stizostedion vitreum, larvae in culture ponds (1999)
    Springer
    Hydrobiologia 400 (1999), S. 129-140 
    Details
    ISSN: 1573-5117
    Keywords: fish ; energetics ; temperature ; feeding ; prey abundance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract I examined food consumption and growth of walleye larvae in extensive culture ponds using direct methods and a bioenergetics model, and compared my results with laboratory feeding and growth studies. Walleye showed a diel pattern of increasing gut fullness during daylight hours. Larvae exhibited lower maximum food consumption rates in the ponds than predicted from previous short-term laboratory feeding studies. Direct estimates and bioenergetics model estimates of daily food consumption in the culture ponds were in poor agreement and the discrepancy varied with respect to walleye size. Food consumption rates in the ponds were related to walleye size (direct estimates) or water temperature (bioenergetics model estimates) but not zooplankton abundance. Growth exceeded 0.10 g g−1 d−1 for all but one sampling interval and the maximum growth rate in the culture pond fish was double the maximum growth rate determined in the laboratory. Growth was positively related to pond temperature and negatively related to walleye mass, but was not significantly related to zooplankton abundance. Gross conversion efficiency was negatively related to walleye mass, positively related to zooplankton abundance and not related to temperature. Food consumption and growth of walleye larvae in the field may be food-limited at much lower prey abundances than previous laboratory research has suggested.
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    URL: http://dx.doi.org/10.1023/A:1003755115000
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  • 21
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    Fish communities and river alteration in the Seine Basin and nearby coastal streams (1999)
    Springer
    Hydrobiologia 400 (1999), S. 155-166 
    Details
    ISSN: 1573-5117
    Keywords: fish ; Index of Biotic Integrity ; water quality ; habitat diversity ; substrate clogging ; France
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Spatial variation of quality of fish communities in the whole Seine basin and nearby coastal streams were examined by the Index of Biotic Integrity (IBI). The relationship between quality of fish communities and river alteration was also studied. A trend of fish community degradation was found from the periphery to the centre of the basin and from upstream to downstream. This trend is conform with the gradient of anthropic pressures observed in the catchment. Variations in IBI scores were significantly related to water quality, diversity of physical habitat and substrate clogging. In headwaters, effects of water quality and substrate clogging were predominant, suggesting that fish community quality is first linked to land use in the catchment. Downstream, IBI scores were mainly linked with diversity of habitat suggesting that fish community quality principally depends on direct river bed alterations. Relationships between each metric of the IBI and the river features tended to show that reduction of habitat heterogeneity first reduced species richness, whereas degradation of water quality first affected the functional structure of the fish community. These results provide useful elements to develop a global rehabilitation of fish communities at the whole basin scale.
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    URL: http://dx.doi.org/10.1023/A:1003752215677
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  • 22
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    Effects of Body Size and Food Ration on Over-winter Survival and Growth of Age-0 Atlantic cod, Gadus morhua (1999)
    Springer
    Environmental biology of fishes 54 (1999), S. 413-420 
    Details
    ISSN: 1573-5133
    Keywords: mortality ; specific growth rate ; Newfoundland ; fish ; aquaculture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract This study examined the effects of body size and food ration on over-winter survival of age-0 Atlantic cod. Cod were divided into two groups based on standard length (large=76.95±1.10 mm SL; small=57.65±1.02 mm SL; mean±1 SE) and wet weight (large=4.02± 0.21 g; small=1.52±0.09 g). Replicate tanks (n=2) of 10 large and 10 small cod were exposed to one of two food rations (0.25% and 1.0% body weight day-1) for the entire experiment (December to June). Tanks were examined daily for mortalities and feeding was adjusted accordingly. The experiment was run under ambient light and seawater conditions. All but large age-0 cod exposed to the low food ration grew over the course of the experiment. The specific growth rate (SGR) of small cod was significantly higher (0.2425% wet weight day-1) than that of the large fish (0.0443% wet weight day-1). Food ration had no significant influence on SGR or over-winter survival. Significantly more of the large age-0 cod survived the winter (58.5% of those originally introduced) compared to the smaller fish (14%). Our results are consistent with those from studies of several other fish species, and are discussed in relation to the ecology of age-0 cod, and their potential use in aquaculture in Newfoundland.
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    URL: http://dx.doi.org/10.1023/A:1007587101669
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    Are the Indonesian and Western Indian Ocean Coelacanths Conspecific: A Prediction (1999)
    Springer
    Environmental biology of fishes 54 (1999), S. 453-456 
    Details
    ISSN: 1573-5133
    Keywords: Latimeria ; fish ; distribution ; geological history ; India ; river flow ; effects of siltation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract It is hypothesized that the ancestor of the extant western Indian Ocean and Indonesian populations of Latimeria was continuously distributed along the deeper coasts of massed Africa–Madagascar–Eurasia in early geologic time. The collision of India with Eurasia, roughly 50 MY ago, caused the formation of the Himalayan Mountains and subsequent developement of numerous rivers. The rivers, which flow down both coasts of India, and areas even further east, deposited, and continue to deposit, great amounts of silt along both coasts of India. The siltation destroyed possible coelacanth habitats, thus isolating coelacanth populations to the west of India from those to the east and allowing them to diverge.
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    URL: http://dx.doi.org/10.1023/A:1007524929593
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  • 24
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    Black Male Bellies and Red Female Throats: Color Changes with Breeding Status in a Threespine Stickleback (1999)
    Springer
    Environmental biology of fishes 55 (1999), S. 237-244 
    Details
    ISSN: 1573-5133
    Keywords: black nuptial coloration ; female coloration ; Gasterosteus aculeatus ; parental success ; fish
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract This paper provides the first report of black nuptial coloration on the ventral side for a population of threespine sticklebacks, Gasterosteus aculeatus, in Northern California. Black nuptial coloration was least intense during precourtship. Although the black coloration intensified during courtship, it was not a significant predictor of female choice and, unlike the red throat and blue eyes, was not inversely correlated with the number of female introductions necessary before spawning occurred. Black coloration was the most intense for males who successfully hatched embryos, supporting a parental-defense role late in the cycle. Unsuccessful fathers had more intensely colored red throats, blue eyes, and black bellies during most of the reproductive cycle than successful fathers. Some females in this study developed red coloration on their throat, although none to the intensity or distribution typical of a breeding male.
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    URL: http://dx.doi.org/10.1023/A:1007572620424
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  • 25
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    Fall and Early Winter Movements of Cutthroat Trout, Oncorhynchus clarki, in Relation to Water Temperature and Ice Conditions in Dutch Creek, Alberta (1999)
    Springer
    Environmental biology of fishes 55 (1999), S. 359-368 
    Details
    ISSN: 1573-5133
    Keywords: fish ; salmonid ; aggregation ; anchor ice ; groundwater ; behaviour
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Fall and winter movement and behaviour of 28 cutthroat trout Oncorhynchus clarki was determined using radiotelemetry to evaluate the effects of water temperature and ice conditions. As water temperatures decreased, cutthroat trout moved from more solitary positions to aggregations. With few exceptions, radiotagged fish aggregated with other fish in groups varying from 5 to approximately 70 fish. The percentage of fish aggregating and the mean size of aggregation was negatively correlated with water temperature. The mean distance moved by radiotagged cutthroat trout from 1 September to 12 January was 1.0 km. After forming aggregations, fish tended to stay within a 120 m length of stream until the end of tracking in mid-January. Fish that were less sedentary after their initial overwintering movement usually moved when their habitat was occluded by anchor ice. These fish moved thirty times farther and six times more often than fish in stable overwintering areas. In Dutch Creek multiple freezing events caused several ice related habitat exclusions and movements associated with large decreases in air temperature. Several bull trout and mountain whitefish were observed in groups with cutthroat trout.
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    URL: http://dx.doi.org/10.1023/A:1007519419492
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    A Sexual Preference in the Amazon Molly, Poecilia formosa (1999)
    Springer
    Environmental biology of fishes 56 (1999), S. 325-331 
    Details
    ISSN: 1573-5133
    Keywords: video-playback ; Poeciliidae ; mate choice ; sexual selection ; gynogen ; fish ; ontogeny
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The Amazon molly, Poecilia formosa, is an all-female species that reproduces by gynogenesis, i.e., it relies on sperm of males of closely related species to trigger embryogenesis. Sperm is supplied by males of P. latipinna and P. mexicana. Amazon mollies live in sympatry with at least one of these species, a few populations live in sympatry with two sperm-donor species. As P. formosa is sperm dependent, it needs mechanisms for species and mate recognition. To investigate the effect of rearing conditions on sexual preferences of Amazon mollies, we raised Amazon mollies in sympatry with P. latipinna and P. mexicana males. We used simultaneous choice tests to determine the effect of age on female sexual preferences. Immature Amazon mollies do not exhibit a preference if given a choice between a P. latipinna and a P. mexicana male, whereas adult P. formosa do have a preference for the P. latipinna male. We used two different stimuli in this study, live males and videotapes of males.
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    URL: http://dx.doi.org/10.1023/A:1007501822540
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  • 27
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    Spawning Season Variations of Female Nile Tilapia, Oreochromis niloticuss, From Man-made Lakes of Côte D'Ivoire (1999)
    Springer
    Environmental biology of fishes 56 (1999), S. 375-387 
    Details
    ISSN: 1573-5133
    Keywords: seasonality ; inter-annual variations ; fish ; cichlid
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The spawning season of Oreochromis niloticus females was studied over two annual cycles in 6 small agropastoral and 2 large hydroelectric reservoirs of Côte d'Ivoire (Ayamé and Kossou), situated between 5 and 10°N of latitude. Reproduction occurred during a marked season in the agropastoral reservoirs and in Lake Ayamé, whereas it was continuous in Lake Kossou. Spawning season differed between reservoirs and among years within the same reservoir. Seasonal changes in temperature, rainfall, day length, chlorophyll a concentration and water level often corresponded with changes in the annual spawning cycle. However, annual periodicity of O. niloticus reproduction was more likely influenced by the ephemerides cycle.
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    URL: http://dx.doi.org/10.1023/A:1007588010824
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  • 28
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    Internal phosphorus loading in Lake Ringsjön (1999)
    Springer
    Hydrobiologia 404 (1999), S. 19-26 
    Details
    ISSN: 1573-5117
    Keywords: sediment ; phosphorus ; eutrophication ; biomanipulation ; fish ; Sweden
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Lake Ringsjön did not respond with decreased algal production following a substantial reduction in external phosphorus loading. This is typical of many shallow lakes which for decades have received excessive amounts of nutrients. The inertia is due to large amounts of phosphorus (P) stored in sediments and biota, causing internal phosphorus loading. Much of this phosphorus is thought to be released from the organic-rich profundal sediments. In Lake Ringsjön, only one third of the total bottom area is covered by such sediments, the rest being dominated by sand and silt. In the profundal sediments bulk P content was not exceptionally high (approximately 2 mg P·g DW−1), while the pore water phosphate concentrations, especially in Sätofta Basin, were very high, indicating large potential for phosphorus release to the water. This is also indicated by the large proportion of Fe- and Al-bound P in the sediments of Sätofta Basin. Although there are no direct quantifications of phosphorus release from the sediments in Lake Ringsjön, measurements of phosphorus concentrations in the water mass as well as budget calculations for the three basins clearly show a high capacity for internal loading. Phosphorus concentrations generally increase during summer, when external additions are minimal. Until 1980, the annual external phosphorus addition to Lake Ringsjön greatly exceeded the output, showing that the lake was an efficient phosphorus trap. Since then, input and output have been balanced, but in recent years signs that the lake is once again retaining phosphorus on an annual basis are evident. There are marked differences between the three basins, with Western Basin generally retaining phosphorus, while the upstream Eastern Basin and Sätofta Basin during the 1980s often exported phosphorus. It is not possible to evaluate the effects of the fish biomanipulation on the internal loading of phosphorus from the sediment.
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    URL: http://dx.doi.org/10.1023/A:1003705520085
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  • 29
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    Internal phosphorus loading in Lake Ringsjön (1999)
    Springer
    Hydrobiologia 404 (1999), S. 19-26 
    Details
    ISSN: 1573-5117
    Keywords: sediment ; phosphorus ; eutrophication ; biomanipulation ; fish ; Sweden
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Lake Ringsjön did not respond with decreased algal production following a substantial reduction in external phosphorus loading. This is typical of many shallow lakes which for decades have received excessive amounts of nutrients. The inertia is due to large amounts of phosphorus (P) stored in sediments and biota, causing internal phosphorus loading. Much of this phosphorus is thought to be released from the organic-rich profundal sediments. In Lake Ringsjön, only one third of the total bottom area is covered by such sediments, the rest being dominated by sand and silt. In the profundal sediments bulk P content was not exceptionally high (approximately 2 mg P·g DW−1), while the pore water phosphate concentrations, especially in Sätofta Basin, were very high, indicating large potential for phosphorus release to the water. This is also indicated by the large proportion of Fe- and Al-bound P in the sediments of Sätofta Basin. Although there are no direct quantifications of phosphorus release from the sediments in Lake Ringsjön, measurements of phosphorus concentrations in the water mass as well as budget calculations for the three basins clearly show a high capacity for internal loading. Phosphorus concentrations generally increase during summer, when external additions are minimal. Until 1980, the annual external phosphorus addition to Lake Ringsjön greatly exceeded the output, showing that the lake was an efficient phosphorus trap. Since then, input and output have been balanced, but in recent years signs that the lake is once again retaining phosphorus on an annual basis are evident. There are marked differences between the three basins, with Western Basin generally retaining phosphorus, while the upstream Eastern Basin and Sätofta Basin during the 1980s often exported phosphorus. It is not possible to evaluate the effects of the fish biomanipulation on the internal loading of phosphorus from the sediment.
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    Trophic dynamics in turbid and clearwater lakes with special emphasis on the role of zooplankton for water clarity (1999)
    Springer
    Hydrobiologia 408-409 (1999), S. 217-231 
    Details
    ISSN: 1573-5117
    Keywords: alternative stable states ; turbid ; clearwater ; macrophytes ; fish ; trophic structure ; bottom-up ; top-down ; shallow lakes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Within a certain nutrient level shallow lakes may alternate between two states, a clearwater and a turbid state. To obtain more information on the characteristics of these two states, we compared seasonal variations in trophic structure and physico-chemical variables of two clear and two turbid lakes studied during seven or eight years. The clearwater lakes were characterised by a high abundance of submerged macrophytes, high piscivorous:planktivorous fish ratios, high zooplankton:phytoplankton ratios and low chlorophyll aduring summer. Submerged macrophytes were almost absent from the turbid lakes, planktivorous fish dominated, the zooplankton:phytoplankton ratio was low and summer chlorophyll awas high. While total phosphorus (TP) was almost constant throughout the season in the clearwater lakes, TP was substantially higher during summer in the turbid lakes reflecting high internal loading. In the clearwater lakes, mean summer chlorophyll awas only 45–51% of winter values, while summer chlorophyll awas 118–259% of winter values in the turbid lakes. Our data suggests that zooplankton, by grazing on phytoplankton, play a major role in maintaining clearwater conditions in eutrophic macrophyte-rich lakes, in particular during summer. In addition, results from a multiple regression on data from 37 lakes and the analyses of the seasonal dynamics in suspended solids provide some evidence that zooplankton grazing diminishes concentrations of detritus and inorganic suspended solids either directly by grazing or more indirectly. Using information also from literature, we argue that the role of zooplankton grazing for water clarity in macrophyte-rich lakes may increase from mesotrophic to eutrophic lakes.
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    URL: http://dx.doi.org/10.1023/A:1017071600486
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    Intraspecific Variations in Size- and Age-at-maturity for Red Bandfish, Cepola macrophthalma (1999)
    Springer
    Environmental biology of fishes 54 (1999), S. 151-160 
    Details
    ISSN: 1573-5133
    Keywords: Aegean Sea ; length-at-maturity ; intraspecific variations ; fish
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Intraspecific variations in size- and age-at-maturity were studied in red bandfish, Cepola macrophthalma, in two adjacent gulfs of the western Aegean Sea, in the southern of which the population of red bandfish is stunted. Samples were collected with a commercial trawler over a grid of 34 stations at depths ranging from 22 to 222 m. The hypothesis tested was that length and age at 50% maturity, Lm50 and tm50 respectively, for males and females do not differ in the two regions. The results showed that the Lm50 of both males and females in the northern area was by 3.5 cm larger than that in the southern area and the 95% confidence intervals of Lm50 in the two areas did not overlap. Although the tm50 of males was larger in the northern area, the 95% confidence intervals of tm50 overlapped in the two areas whereas for females, the tm50 was larger by 0.4 years in the northern area and the 95% confidence intervals of tm50 in the two areas did not overlap. Stunting of the red bandfish growth in the southern area is the result of the combination of an extremely low food availability with higher temperatures prevailing in that area. Implications of these fine spatial scale intraspecific differences for the fisheries management of the highly oligotrophic eastern Mediterranean Sea are also discussed.
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    URL: http://dx.doi.org/10.1023/A:1007594719450
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    Effects of thermal regime on energy and nitrogen budgets of an early juvenile Arctic charr, Salvelinus alpinus, from Lake Inari (1999)
    Springer
    Environmental biology of fishes 54 (1999), S. 219-227 
    Details
    ISSN: 1573-5133
    Keywords: temperature ; energy partitioning ; nitrogen balance ; salmonid ; fish
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The feed intake, growth, oxygen consumption and ammonia excretion of juvenile Arctic charr were measured over period of four weeks at different temperatures which were either constant (11.0, 14.4, 17.7 °C) or fluctuated daily (14.3 ± 1 °C). Maximum feed intake was estimated to occur at 14.3 °C, while oxygen consumption and nitrogen excretion were highest at the highest temperature, and growth rate was estimated to be highest at 13.9 °C. Feed conversion efficiency was estimated to be highest at 13.2 °C, where over 62.7% of ingested energy was allocated to growth. Metabolic rate accounted for 16–30% of ingested energy and nitrogen excretion was under 3% of ingested energy. The nitrogen budget was under similar thermal influences to the energy budget. Thermal fluctuation increased metabolic rate, but not feed intake, leading to a reduction in feed conversion efficiency under fluctuating temperature conditions.
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    URL: http://dx.doi.org/10.1023/A:1007566806749
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    Life History of Black Seabream, Spondyliosoma cantharus, off the Canary Islands, Central-east Atlantic (1999)
    Springer
    Environmental biology of fishes 54 (1999), S. 325-336 
    Details
    ISSN: 1573-5133
    Keywords: population structure ; reproduction ; growth ; mortality ; fish
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Black seabream, Spondyliosoma cantharus, caught off the Canary Islands is characterized by a protogynous hermaphroditism. The size range of the catches is between 8 and 40 cm, with a main distribution between 16 and 24 cm. The mean length of the individuals shows an increase with increasing depth. Males:females ratio is unbalanced in favour of females (1:2.18). The reproductive season extends from late autumn to mid spring, with a peak in spawning activity in January–February. A dichromatism is found between males and females during the spawning season. Males reach maturity at a larger total length, 22.7 cm (3 years old), than females, 17.3 cm (2 years old). Morphometric relationship between length and mass for the whole population is described by the parameters: a=0.00732, and b=3.24747. Otoliths age readings indicate that the exploited population consists of eleven age groups (0–X years), including a very high proportion of individuals between 2 and 3 years old. The von Bertalanffy growth parameters for the whole population are: L∞=43.35 cm, k=0.24 year−1, and t0=−0.11 year. The rates of total, natural and fishing mortality are 1.36, 0.52 and 0.84 year−1, respectively. The length at first capture is 16.8 cm. The exploitation rate indicates that the stock is overfished.
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    URL: http://dx.doi.org/10.1023/A:1007515301745
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    Gill Morphometry in Growth Hormone Transgenic Atlantic Salmon (1999)
    Springer
    Environmental biology of fishes 54 (1999), S. 405-411 
    Details
    ISSN: 1573-5133
    Keywords: Salmo salar ; exchange area ; secondary lamellae ; fish ; gas exchange ; respiratory system ; functional morphology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We show that many of the morphological features of the respiratory system of growth enhanced transgenic salmon are greater than those of similarly sized control salmon. Growth hormone transgenic Atlantic salmon, Salmo salar were the F2 generation produced using eggs from a transgenic F1 female and milt from a nontransgenic male. At the time the gill tissues were sampled, the transgenic salmon were growing 2.1 times more rapidly than the nontransgenic control salmon, and they had oxygen uptake rates that were about 1.6 times greater than control salmon. In the present study we show that the gill surface area available for respiratory exchange in the transgenic salmon is about 1.24 times that in control salmon which does not parallel the 1.6 elevation in oxygen uptake. The increase in gill exchange area was due largely to a relatively uniform increase in length of each gill filament.
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    URL: http://dx.doi.org/10.1023/A:1007574308129
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    Influence of Light Preferences on the Avoidance Responses of Lake Whitefish, Coregonus clupeaformis, to Cadmium (1999)
    Springer
    Environmental biology of fishes 55 (1999), S. 295-306 
    Details
    ISSN: 1573-5133
    Keywords: fish ; behaviour ; contaminant ; salmonid
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The avoidance responses of lake whitefish to cadmium were studied in a counter-current trough where Cd was added to a shaded area to which whitefish were strongly attracted. In the first experiment, responses of individual fish to sequentially increasing Cd concentrations were monitored over a 1.6 h period. Whitefish did not start to move out of the shaded, Cd-treated side until a concentration of 125 µg l-1 was reached, and did not abandon this side except at the highest test concentration (250 µg l-1). This was 50 times the concentration at which whitefish avoided Cd (5 µg l-1) under uniform light conditions. In a second experiment, responses to a single high Cd concentration (150 µg l-1) were monitored over a 18.5 h period (4.5 h light:12 h dark:2 h light) in the same shaded test arena and Cd exposure conditions as above. During the initial light period Cd was avoided to the same degree as that observed at the same concentration in the first experiment, i.e. while some Cd avoidance was evident, fish remained attracted to the shaded, but Cd-treated side; this avoidance remained consistent until darkness (4.5 h). Once the light gradient was replaced with uniform darkness, avoidance of Cd became very strong, surpassing that observed under uniform lighted conditions. However, this response was transitory; after 10 h, Cd avoidance under total darkness returned to levels near those observed under daylight conditions with no light gradient present. Once the lights came back on (light gradient reestablished), fish were again attracted to the shaded side, and avoidance of Cd diminished, returning to the same level as that observed at the start of exposure. The above results demonstrate that when whitefish encounter competing gradients of Cd and light, attraction to favourable light conditions can strongly suppress avoidance of toxic concentrations of Cd, even over an extended period.
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    Variation in Gillraker Number During Growth of the Sea Bass, Dicentrarchus labrax (Perciformes: Moronidae), Reared at Different Salinities (1999)
    Springer
    Environmental biology of fishes 55 (1999), S. 391-398 
    Details
    ISSN: 1573-5133
    Keywords: ecophenotypism ; branchial sieve ; geographic variation ; fish ; meristics ; taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A marked salinity-related decrease in gillraker number in sea bass samples during growth was documented. All specimens share the same genetic stock and rearing conditions were constant during early ontogeny. Variation in gillraker number could be related to the ecophenotypism of this character but selection can not be excluded. Results obtained from reared specimens were compared with those reported in the literature and with data collected from wild stocks. Attention is focused on the pitfalls that the use of this character may have on the taxonomy of fish species.
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    URL: http://dx.doi.org/10.1023/A:1007548102060
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    Aspects of the Feeding and Reproductive Biology of the Lake Tanganyikan Cichlid, Lamprologus ornatipinnis (Pisces, Cichlidae) (1999)
    Springer
    Environmental biology of fishes 55 (1999), S. 431-441 
    Details
    ISSN: 1573-5133
    Keywords: diet ; gonadosomatic index ; seasonality ; dentition ; fish
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract This project investigated the reproductive and feeding biology of Lamprologus ornatipinnis. Specimens were collected monthly from North Bay, Mbita Island, Zambia for a year. Dentition was examined under a scanning electron microscope, stomach contents were analysed using the Index of Relative Importance (IRI) and mean Gonado-somatic Indices (GSI) were calculated for each month to reveal spawning peaks. Both males and females possess an outer row of six (premaxilla) and eight (dentary) enlarged canines. The remaining inner rows consist of small, recurved canine-like teeth. The lower pharyngeal bone possesses enlarged centrally placed molars with an increasing number of smaller bevelled teeth laterally. This dentition is very similar to a typical benthic arthropod and mollusc eater. Stomach content analysis revealed that L. ornatipinnis feeds predominantly on Chironomidae, Copepoda and Ostracoda. The importance of these prey items in the diet differed significantly between the months sampled. Percentage volume of Copepoda and Cyclopoida was greater in female stomachs than males and the % number of Chironomidae greater in males than females. Gonadosomatic Index (GSI) values indicated males and females breed throughout the year. Females, however have a significant peak (p〈0.05) in breeding activity from July to October that coincides with the increased abundance of plankton at this time.
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    Response to Video and Computer-animated Images by the Tiger Barb, Puntius tetrazona (1999)
    Springer
    Environmental biology of fishes 56 (1999), S. 317-324 
    Details
    ISSN: 1573-5133
    Keywords: video playback ; television ; schooling behavior ; fish
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Video playback has become an important tool for testing certain questions about animal visual perception. While a few studies have compared the response of test subjects to live and video stimuli, it is generally assumed a priori that the animals will respond to the video image as if it were ‘real’. Since video devices are tuned to the spectral sensitivities and flicker fusion frequencies of the human eye and brain, it is important to conduct preliminary tests to compare the response of test subjects between live and video images. Here we compare schooling behavior of tiger barbs, Puntius tetrazona, when presented with a school of live fish, an analog video school of fish and a video of a computer-animated school of fish. Test subjects did not show a significantly different schooling behavior response to any of these stimuli. Additionally, when given the choice of schooling with a conspecific versus a heterospecific, tiger barbs schooled significantly more often with the conspecifics for all three stimulus formats. This study provides evidence that tiger barbs do not choose to discriminate between live and video models of fish and that this technique can be used to test future questions concerning visual perception for this species.
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    URL: http://dx.doi.org/10.1023/A:1007549721631
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    Do digestive enzymes set a physiological limit on growth rate and food conversion efficiency in the Atlantic cod (Gadus morhua)? (1999)
    Springer
    Fish physiology and biochemistry 20 (1999), S. 293-303 
    Details
    ISSN: 1573-5168
    Keywords: acid proteases ; alkaline phosphatase ; chymotrypsin ; digestive enzymes ; fish ; food intake ; glutamyltransferase ; growth hormone ; protein content ; trypsin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The objective of this study was to determine the potential sites of maximal growth limitation in Atlantic cod (Gadus morhua). Forty cod were reared in ten sea water tanks. Fish were randomly divided into 5 groups, a control group (injected with saline solution) and 4 experimental groups that received different levels of recombinant bovine somatotropin (rbST: 1.0, 2.0, 4.0 and 10.0 μg g fish−1 2 weeks−1) by injection in the abdominal cavity. Fish were fed ad libitum 3 times a week during four weeks. We measured individual body mass, growth rate, food intake and food conversion efficiency. At the end of the experiment, we measured the activity of acid proteases in the stomach; trypsin and chymotrypsin in the pyloric caeca; alkaline phosphatase (ALP) and glutamyltransferase (GGT) in the intestine. No significant differences were observed in growth rate, food intake or food conversion efficiency among the five groups. Trypsin, chymotrypsin, ALP and GGT activities when expressed in U g fish−1 were correlated with growth rate. These enzymes were also correlated with food ingestion except for trypsin when expressed in U mg protein−1. Trypsin was the only enzyme that showed a significant correlation with food conversion efficiency. Our conclusion is that, at the level of digestion, trypsin is the only enzyme measured that could be suspected to potentially limit growth rate in cod.
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    Fish hepatocyte glycogen phosphorylase – a sensitive indicator for hormonal modulation (1999)
    Springer
    Fish physiology and biochemistry 21 (1999), S. 15-24 
    Details
    ISSN: 1573-5168
    Keywords: caffeine ; catecholamines ; fish ; glucose production ; liver ; method/assay ; phosphorylation ; prostaglandin E2
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The absence of a reproducible method for the assay of glycogen phosphorylase (GPase) in isolated fish hepatocytes has made the interpretation of hormone-induced glycogenolysis data difficult. This study presents such an assay and demonstrates its sensitivity to hormonal activation. The enzyme is assayed in the reverse direction using glucose 1-phosphate (G1-P) and glycogen as substrates and uses standard methods for the quantification of the liberated inorganic phosphate. The assay is highly reproducible, sensitive, and provides an excellent means to follow small and rapid changes in enzyme phosphorylation status following the addition of hormones. We show for hepatocytes isolated from rockfish (Sebastes caurinus) and brown bullhead (Ameiurus (Ictalurus) nebulosus) that small concentrations of three model hormones, namely epinephrine (catfish), norepinephrine, and prostaglandin E2 (rockfish), lead to the rapid, concentration and time-dependent conversion of existing GPase into the active GPase a form. Some of the enzyme seems to be impervious to hormonal activation, as the highest %GPase a never reaches 100%. We provide evidence that changes in enzyme phosphorylation status provide a better short-term insight into hormone-dependent activation than estimates of glucose or some other end products, that usually must accumulate for long periods before detection is possible. Our data also show that GPase in freshly isolated hepatocytes is already in an activated state and cells should be given a period of ‘rest’ for several hours before hormonal studies involving glycogen breakdown or the cAMP cascade are initiated.
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    What determines the size of teleost erythrocytes? Correlations with oxygen transport and nuclear volume (1999)
    Springer
    Fish physiology and biochemistry 20 (1999), S. 31-35 
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    ISSN: 1573-5168
    Keywords: aerobic scope ; blood ; erythrocyte volume ; fish ; haemoglobin ; metabolism ; nuclear volume ; oxygen transport
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract An inverse relationship exists between erythrocyte size and the aerobic swimming ability of teleosts. A functional basis for this relationship is found in larger surface area to volume ratios and shorter diffusion distances allowing more rapid oxygen transfer as erythrocyte volume decreases. However, this apparently simple functional relationship is confounded by a more general direct relationship between cell size and nuclear volume. Nuclear DNA content, which is directly proportional to nuclear volume, is known to vary at least 11 fold among teleost species. Therefore a question arises as to the relative contributions of nuclear volume and the demands of the blood oxygen delivery system in determining erythrocyte volume. These relationships were investigated by regressing erythrocyte volume against nuclear volume and whole blood haemoglobin concentration (as an index of aerobic scope) for 52 species of teleost fish from 25 families. This analysis shows that erythrocyte volume is more highly correlated with oxygen delivery than with nuclear volume. However, much of the variation in erythrocyte volume is unexplained.
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    An 11-ketotestosterone induced kidney-secreted protein: the nest building glue from male three-spined stickleback, Gasterosteus aculeatus (1999)
    Springer
    Fish physiology and biochemistry 20 (1999), S. 79-85 
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    ISSN: 1573-5168
    Keywords: fish ; SDS-PAGE ; amino acid composition ; glycoprotein
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In male three-spined sticklebacks, Gasterosteus aculeatus, the kidney hypertrophies during the breeding season and produces a glue which is used in nest-building. This hypertrophy is androgen dependent with 11-ketotestosterone (11 KT) being most effective. The aim of the present study was to characterize the protein composition of this glue. Threads of glue were collected from stickleback nests and glue material was sampled from the content of urinary bladders of male sticklebacks in breeding condition. The samples were investigated using sodium dodecyl sulphate- polyacrylamide gel electrophoresis (SDS-PAGE). One major glycoprotein dominated in both the nest-threads and urinary bladder samples. The identified glycoprotein had a molecular mass of approximately 203 kDa. After deglycosylation the molecular mass was approximately 200 kDa. The amino acid composition of the protein from urinary bladder content was almost identical to the amino acid composition of the protein from the nest-threads. The protein had a relatively high content of cysteine (7.6–8.0%). The glycoprotein was named spiggin. Spiggin was absent in the urinary bladder of untreated castrated fish, but spiggin was present in sham- operated fish and in castrated fish treated with 11 KT. These results demonstrate that spiggin is induced by 11 KT. Spiggin is so far the only protein known to be induced by 11KT and based on the present findings we suggest that spiggin represents a novel structural protein.
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    Temporal changes in tissue metabolic capacities of wild Atlantic cod Gadus morhua (L.), from Newfoundland (1999)
    Springer
    Fish physiology and biochemistry 20 (1999), S. 181-191 
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    ISSN: 1573-5168
    Keywords: fish ; white muscle ; aerobic metabolism ; anaerobic metabolism ; growth rate ; seasons
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We used biochemical indicators to assess the physiological status of Atlantic cod (Gadus morhua) sampled at different sites and times along the Newfoundland coast. The physiological status of cod changed more with time of sampling and size of the cod than with the site of sampling. The levels of muscle glycolytic enzymes and proteins suggest that cod from both near shore and offshore environments experienced the most favorable conditions in late summer and early fall. In small cod sampled near shore, increases in muscle aerobic capacity and protein contents accompanied the decrease in temperature from September to December. The positive allometry of muscle glycolytic capacities was more apparent in samples obtained in early winter than at other times, suggesting that the energetic status of cod affects the expression of this allometric relationship. On the other hand, a negative allometry of muscle aerobic capacities was apparent throughout the study. Reproductive maturity had few effects upon the biochemical parameters measured and tended to favor mature over immature cod. Our results suggest that cod in these areas were only growing in fall.
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    Cellular distribution of insulin-like growth factor II (IGF-II) mRNA and hormonal regulation of IGF-I and IGF-II mRNA expression in rainbow trout testis (Oncorhynchus mykiss) (1999)
    Springer
    Fish physiology and biochemistry 20 (1999), S. 219-229 
    Details
    ISSN: 1573-5168
    Keywords: fish ; gene expression ; GH ; GtH ; gonad ; growth factors ; RT-PCR ; salmonid
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In this study, Northern blot analysis of RNA from trout testis revealed a single transcript of insulin-like growth factor II (IGF-II) around 4.7 kb. The cellular distribution of IGF-II mRNA was studied and quantified in different testicular cells enriched populations by RT-PCR. IGF-II mRNA appears to be expressed in all cellular types tested: spermatogonia A and B, primary spermatocytes, spermatids and secondary spermatocytes and Sertoli cells. A significantly higher expression of IGF-II was found in premeiotic germ cells. The levels of IGF-II mRNA appear to be higher than those of IGF-I in immature trout testis, as judged from the semi-quantitative RT-PCR results. These data suggest that in addition to IGF-I, IGF-II may play a role in testicular physiology in fish. The hormonal regulation of IGF-I and IGF-II gene expression was investigated both in vitro and in vivo using RT-PCR approach. Gonadotropin (GtH) added to testicular explants increased IGF-II mRNA levels but had no effect on IGF-I. No statistically significant effect was observed with androgens. In vivo, GH and pituitary extracts resulted in an 8 fold and 2-3 fold increase in both IGF-I and IGF-II mRNA levels, respectively. Taken together, our study suggests that IGF-I and IGF-II may act as local mediators of GH and GtHs in fish testis. Moreover, our results imply that in fish testicular cells, IGFs are potential paracrine/autocrine regulators inside the spermatogenic compartment and can act directly on germ cells to stimulate their proliferation.
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    Effects of experimental hypo- and hyperthyroidism on iodothyronine deiodinases in Nile tilapia, Oreochromis niloticus (1999)
    Springer
    Fish physiology and biochemistry 20 (1999), S. 201-207 
    Details
    ISSN: 1573-5168
    Keywords: thyroid hormone ; deiodination ; fish ; tilapia ; hyperthyroidism ; hypothyroidism ; methimazole ; porcine follicle stimulating hormone ; T3 ; T4
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In the present study, we examined the effects of experimentally-induced increases or decreases in plasma concentrations of thyroid hormones on iodothyronine deiodinases in tilapia, Oreochromis niloticus. To obtain hyperthyroid tilapia, fish were injected with porcine follicle stimulating hormone (pFSH) 36 hours before sampling or fed on demand for 11 days with tilapia pellets containing 12 ppm T3. Tilapias were made hypothyroid by providing them food containing 0.2% methimazole for 11 days. Plasma T4 and T3 and the in vitro deiodinase activity in liver, kidney, brain and gill were measured at the end of the treatment period. Injection with pFSH caused an increase in plasma T4 but had no influence on plasma T3 levels. A small increase in plasma T3 was observed in T3-fed fish. Plasma levels of both T4 and T3 were decreased by methimazole treatment. We observed no changes in kidney type I deiodinase (D1), whereas liver type II deiodinase (D2) was increased during hypothyroidism and decreased during hyperthyroidism. Hypothyroidism resulted in a significant decrease in brain, gill and liver type III deiodinase (D3). An pFSH-induced increase in T4 stimulated brain and gill D3 but not liver D3, whereas the opposite was true in T3-fed fish. We conclude that the regulation of D1 and D3 in tilapia is probably different compared to mammals.
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    Close association of gonadotropin-releasing hormone fibers and gonadotropin, growth hormone, somatolactin and prolactin expressing cells in pejerrey, Odontesthes bonariensis (1999)
    Springer
    Fish physiology and biochemistry 21 (1999), S. 121-127 
    Details
    ISSN: 1573-5168
    Keywords: fish ; immunocytochemistry ; pituitary gland ; pituitary hormones
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The purpose of this study was to determine if there is any association between immunoreactive (ir) gonadotropin-releasing hormone (GnRH) fibers with different pituitary endocrine cell types in the pejerrey, Odontesthes bonariensis. Using a monoclonal antibody raised against mammalian GnRH (mGnRH) (LRH13), ir-GnRH fibers were observed passing through the pituitary stalk and reaching the three areas of the pituitary gland: rostral (RPD) and proximal pars distalis (PPD) and pars intermedia (PI). Double labeled immunocytochemistry showed ir-GnRH fibers in close association with prolactin (PRL)-producing cells in the RPD, growth hormone (GH)-producing cells in the PPD, gonadotropin (GtH)-producing cells in the PPD and the external border of the PI, and with somatolactin (SL)-producing cells in the PI. Our results show, direct morphological evidences of a close association of GnRH fibers with GH, PRL, GtH and SL-expressing cells. These results would suggest that GnRH has a broad role in the regulation of the secretion of different pituitary hormones.
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    Biochemical characterization of growth hormone receptor in rainbow trout (Oncorhynchus mykiss) before and after purification (1999)
    Springer
    Fish physiology and biochemistry 21 (1999), S. 111-120 
    Details
    ISSN: 1573-5168
    Keywords: fish ; GH ; GH-R ; liver
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The aim of this work was to verify if, compared to mammals, the lower molecular weight of GH-R previously reported in salmonid is real or due to the experimental process. For this purpose, we compared the apparent molecular weight of GH-R, obtained by SDS-PAGE after cross-linking with 50 I-rtGH, obtained from rainbow trout crude liver membrane preparation, incubated in different buffers with those obtained after purification with affinity chromatography. Using crude liver membrane preparation, two specific bands of 50 I-rtGH-protein complex were observed: the major one corresponds to a MW of 70 kDa and the minor one to 45 kDa. However, the pattern of electrophoresis varied according to the different incubation buffers tested. Digestion of the cross-linked complex with β-galactosidase and phospholipase did not significantly modify the position of bands, whilst N-glycosidase F induced a large smear including 4 more pronounced bands (50, 65, 97 and 〉 130 kDa), the heavier band corresponding to the most intensive signal. GH receptors were purified using solubilisation and affinity chromatography. The yield of the liver GH-R from crude liver membrane preparation by the solubilization technique was optimized (48%) using Triton 1% for 1 h (12 °C ). Specific binding sites in the solubilized membrane proteins were saturable when incubated with increasing 50 I-rtGH concentrations, and revealed a high affinity constant (Ka=0.7×109 M−1). After affinity chromatography, specific binding activity was increased 64,000 fold. However, the purity of the preparation was partial and the purification yield was very low (about 0.3%). This enriched fraction, analysed by SDS-PAGE after cross-linking, showed a very intense band (about 63 kDa) which disappeared with an excess of cold rtGH. These results suggest that the lower molecular weight observed in salmonid (41 kDa), compared to mamals, is not due to the experimental process. The significance of GH-R size difference between salmonids and mammals is discussed.
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    Diel changes in plasma arginine vasotocin, isotocin, and melatonin in rainbow trout (Oncorhynchus mykiss) (1999)
    Springer
    Fish physiology and biochemistry 21 (1999), S. 141-146 
    Details
    ISSN: 1573-5168
    Keywords: fish ; hormones ; neurohypophysis ; pineal organ ; rhythm ; teleosts
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The diel changes in plasma AVT, IT and Mel in rainbow trout (Oncorhynchus mykiss) were studied to assess potential relationships. Blood was sampled at 05:00, 11:00, 16:00, 22:30 and 05:00 in freshwater-adapted fish and at 22:30 in brackish water-adapted fish maintained under natural photoperiod. A few of the FW-acclimated fish were assigned to one of two experimental groups and adapted to DD or LL lighting regimes. Blood samples were taken at 11:00 and 22:30. Hormones were extracted from plasma by solid phase extraction and determined by high-performance liquid chromatography. Marked diel variations in AVT and Mel were detected in fish maintained under natural photoperiod. Plasma AVT (fmol ml−1) increased during the light to reach the maximal level at the end of that phase (261.7±23.1). Thereafter, AVT concentration decreased and became minimal at 05:00 (68.9±11.5) 3 h before the sunrise. Plasma Mel (pmol ml−1) increased between 16:00 and 22:30 when a peak value was reached (1204.0±55.5). Thereafter, Mel levels decreased and were minimal after the onset of the light phase (242.8±37.0). IT levels displayed no significant diel changes. Linear regression analysis indicated the negative correlation between plasma Mel and AVT for five collecting times of the daily 24 h cycle in freshwater fish and at 22:30 in brackish water fish. A similar correlation occurred at 11:00 in the DD group and at 22:30 in the LL group. To elucidate the character of the Mel-AVT relationships further studies are required.
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    Intracellular pH regulation of rainbow trout and carp thrombocytes (1999)
    Springer
    Fish physiology and biochemistry 21 (1999), S. 269-275 
    Details
    ISSN: 1573-5168
    Keywords: acid-base regulation ; catecholamines ; fish ; sodium-dependent bicarbonate transport ; sodium/proton exchange
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The pH regulation of rainbow trout and carp thrombocytes was investigated using the pH-sensitive fluorescent dye BCECF and a PTI Imagescan image analysis system. The cells were experimentally acidified either using the ammonium chloride prepulse method or perfusing the cells with a saline containing propionate ion. The recovery from the acidification was followed. By using ion substitutions (N-methyl-D-glucamine for sodium; TRIS vs carbon dioxide/bicarbonate buffer) and transport inhibitors (amiloride to inhibit sodium/proton exchange and DIDS to inhibit chloride and bicarbonate dependent acid extrusion mechanisms) the transport pathways were identified. The pH regulatory mechanisms of thrombocytes in both species were similar. The pH recovery after experimental acidification was fully inhibited by removing sodium from the medium. The sodium-dependent acid extrusion had both amiloride-sensitive and DIDS-sensitive components, indicating that both sodium/proton exchange and sodium-dependent bicarbonate transport were involved. The role of sodium-dependent bicarbonate movements in pH regulation was ascertained by showing that pH recovery occurred faster at a high than at a low bicarbonate concentration. Adrenergic stimulation did not affect the intracellular pH.
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    Effects of dietary lipids on body composition and liver function in juvenile red drum, Sciaenops ocellatus (1999)
    Springer
    Fish physiology and biochemistry 21 (1999), S. 249-255 
    Details
    ISSN: 1573-5168
    Keywords: diet ; lipid ; oxidative stress ; α-tocopherol ; cytochrome P450 ; fish
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract This study was conducted to evaluate the effects of different concentrations of dietary lipids on body composition and liver function in juvenile red drum, Sciaenops ocellatus. Diets were formulated to contain 40% crude protein from solvent-extracted menhaden fish meal and 0, 7, 14 or 21% lipid from menhaden fish oil. The basal diet, without supplemental fish oil, contained lipid at 0.4% of dry weight. The diets were fed to groups of 25 juvenile red drum initially averaging 7.3 ± 0.18 g fish−1 in a recirculating culture system for 8 weeks and weight gain was recorded. After an additional 8 weeks, 16 fish from each treatment were sacrificed and the following measurements were recorded: hepatosomatic index (HSI), intraperitoneal fat (IPF) ratio, and liver α-tocopherol, malondialdehyde (MDA) formation, and cytochrome P-4501A activity (measured as 7-ethoxyresorufin O-deethylase (EROD) activity). The activity of alanine and aspartate aminotransferases and concentrations of α-tocopherol also were measured in plasma. Weight gain was significantly (p〈0.05) affected by dietary lipid concentration, with values ranging from 361% of initial weight for fish fed the basal diet to 527% of initial weight for fish fed the diet containing 7% lipid. The HSI and IPF ratio values also were significantly affected by lipid with the lowest values recorded for fish fed the basal diet and the highest values observed in fish fed the diet containing 21% lipid. Increasing dietary lipid significantly increased oxidative stress as reflected in reduced α-tocopherol in liver and plasma and increased MDA formation in the liver, although no overt pathological signs were observed. These findings suggest that lipid concentrations between 7 and 14%, when the diet contains 60 IU vitamin E kg−1, are likely to limit oxidative stress and result in normal physiological responses of red drum.
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    Myofibrillar proteins in white muscle of the developing African catfish Heterobranchus longifilis (Siluriforms, Clariidae) (1999)
    Springer
    Fish physiology and biochemistry 21 (1999), S. 287-301 
    Details
    ISSN: 1573-5168
    Keywords: development ; fish ; myosin heavy chain ; myosin light chain ; polyacrylamide gel electrophoresis ; tropomyosin ; troponin-C ; troponin-I ; troponin-T
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Developmental changes in myofibrillar protein composition were investigated in the myotomal muscle of the African catfish, Heterobranchus longifilis (Clariidae), by several electrophoretic techniques. The main muscle fibres of larvae and the fast-white muscle fibres of juvenile and adult fish were found to express distinct myosin heavy chain and myosin light chain 2 (LC2) isoforms. Three myosin LC2 chains were successively detected, differing by their isoelectric points. In contrast, the alkali light chains remained qualitatively and quantitatively unchanged during fish growth. Actin, α-tropomyosin, and troponin-C (TN-C) were also similar in larval, juvenile, and adult white muscle, but an additional larval tropomyosin isoform was found in the first developmental stages. Two isoforms of troponin-T (TN-T) and troponin-I (TN-I) were synthesised in the course of fish growth. Transition from the larval to the adult isoform was much faster for TN-T than for TN-I. Slow-red muscle myofibrils from adult H. longifilis showed no common component (except actin) with larval, juvenile, or adult fast-white muscle myofibrils. Red myofibrils displayed a single TN-T and a single TN-I isoform, but two isoforms of TN-C. The myofibrillar protein isoforms synthesised at any given developmental stage almost certainly reflect changes in the functional requirements of swimming muscles in the course of fish development.
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    The presence of uric acid, an antioxidantive substance, in fish seminal plasma (1999)
    Springer
    Fish physiology and biochemistry 21 (1999), S. 313-315 
    Details
    ISSN: 1573-5168
    Keywords: antioxidants ; fish ; spermatozoa ; seminal plasma ; urate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract High concentrations of uric acid in seminal plasma of a range of teleost fish species are reported for the first time. Concentrations of urate amounted to 223.4; 121.9–130.0, 355.9, 735.6, 124.0, 192.7 and 148.0 μM for rainbow trout (Oncorhynchus mykiss), yellow perch (Perca flavescens), muskellunge (Esox masquinongy), Northern pike (Esox lucius), carp koi (Cyprinus carpio), bream (Abramis brama), and tench (Tinca Tinca), respectively. Uric acid is an important anti-oxidant, therefore, it has a potential role in protection of fish spermatozoa against oxidative damage.
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    URL: http://dx.doi.org/10.1023/A:1007886121663
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    Comparative cytogenetics in Apareiodon affinis (Pisces, Characiformes) and considerations regarding diversification of the group (1999)
    Springer
    Genetica 105 (1999), S. 63-67 
    Details
    ISSN: 1573-6857
    Keywords: diversification of species ; fish ; karyotypic evolution ; Parodontidae ; sex chromosomes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Comparative cytogenetic studies in Apareiodon affinis (Pisces, Characiformes) from two hydrographic Brazilian basins showed significant divergences related to the general karyotype structure, C‐banding and nucleolar organizer region (NOR) bearing chromosomes. In the upper Paraná basin population, distinct diploid numbers were observed among sexes, the females showing 2n = 55 and the males 2n = 54 chromosomes, characterizing a multiple sex chromosome system of the ZZ/ZW1W2 type. A diploid number equal to 54 chromosomes was found for the Cuiabá river population, without a sex chromosome heteromorphism. However, the occurrence of acrocentric chromosomes represents an unique character for this population. These karyotypic differences indicate that the analyzed populations must represent distinct Apareiodon species.
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    A Connectionist Model of Left-Right Sound Discrimination by the Mauthner System (1999)
    Springer
    Journal of computational neuroscience 6 (1999), S. 121-144 
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    ISSN: 1573-6873
    Keywords: Mauthner ; escape ; artificial neural networks ; connectionism ; acoustic ; localization ; auditory ; fish ; goldfish ; XNOR model ; phase model
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science , Medicine , Physics
    Notes: Abstract Artificial neural networks were used to explore the auditory function of the Mauthner system, the brainstem circuit in teleost fishes that initiates fast-start escape responses. The artificial neural networks were trained with backpropagation to assign connectivity and receptive fields in an architecture consistent with the known anatomy of the Mauthner system. Our first goal was to develop neurally specific hypotheses for how the Mauthner system discriminates right from left in the onset of a sound. Our model was consistent with the phase model for directional hearing underwater, the prevalent theory for sound source localization by fishes. Our second goal was to demonstrate how the neural mechanisms that permit sound localization according to the phase model can coexist with the mechanisms that permit the Mauthner system to discriminate between stimuli based on amplitude. Our results indicate possible computational roles for elements of the Mauthner system, which has provided us a theoretical context within which to consider past and future experiments on the cellular physiology. Thus, these findings demonstrate the potential significance of this approach in generating experimentally testable hypotheses for small systems of identified cells.
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    Energy Fluxes of an Open Water Area in a mid-Latitude Prairie Wetland (1999)
    Springer
    Boundary layer meteorology 91 (1999), S. 495-504 
    Details
    ISSN: 1573-1472
    Keywords: Evaporation ; Heat storage ; Marsh ; Inversion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Concurrent measurements of the surface energy balance components (net radiation, heat storage, and sensible and latent heat fluxes) were made in three communities (open water, Phragmites australis, Scirpus acutus) in a wetland in north-central Nebraska, U.S.A., during May-October, 1994. The Bowen ratio – energy balance method was used to calculate latent and sensible heat fluxes. This paper presents results from the open water area. The heat stored in water (G) was found to play a major role in the energy exchange over the water surface. During daytime, G consumed 45–60% of R n , the net radiation (seasonally averaged daytime G was about 127 W m−2). At night, G was a significant source of energy (seasonally averaged nighttime G was about -135 Wm−). The diurnal pattern of latent heat flux (λ E) did not follow that of R n . On some days, λ E was near zero during midday periods with large R n . The diurnal variability in λ E seemed to be significantly affected by temperature inversions formed over the cool water surface. The daily evaporation rate (E) ranged from 2 to 8 mm during the measurement period, and was generally between 70 and 135% of the equilibrium rate.
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    An improved method for the purification of stellate cells from rat liver with Dichloromethylene Diphosphate (CL2MDP) (1999)
    Springer
    Methods in cell science 21 (1999), S. 19-24 
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    ISSN: 1573-0603
    Keywords: Dichloromethylene diphosphate ; Hepatic stellate cell isolation ; Liposome ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Hepatic perisinusoidal cell population consists of hepatic stellate cells, Kupffer cells, endothelial cells, and Pit cells. These cells are isolated by enzymic digestion and purified by density gradient centrifugation. With isolation of stellate cells, conventional method is unable to eliminate the contamination of Kupffer cells because the densities of these two cells are similar. We report here an improved method for isolation of highly purified hepatic stellate cells, using dichloromethylene diphosphate (CL2MDP), which has selective cytotoxicity of Kupffer cells. Three days after the single intravenous administration of liposome-encapsulated CL2MDP, the Kupffer cells disappeared almost completely from the liver. Following Percoll density gradient centrifugation, the purity of the hepatic stellate cells exceeded 98% without any contamination of the Kupffer cells. Kupffer cells are reported to affect the physiological functions of stellate cells. The availability of highly purified stellate cells will facilitate the investigation of their functions in primary culture.
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    Factors affecting food consumption and growth of walleye, Stizostedion vitreum, larvae in culture ponds (1999)
    Springer
    Hydrobiologia 400 (1999), S. 129-140 
    Details
    ISSN: 1573-5117
    Keywords: fish ; energetics ; temperature ; feeding ; prey abundance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract I examined food consumption and growth of walleye larvae in extensive culture ponds using direct methods and a bioenergetics model, and compared my results with laboratory feeding and growth studies. Walleye showed a diel pattern of increasing gut fullness during daylight hours. Larvae exhibited lower maximum food consumption rates in the ponds than predicted from previous short-term laboratory feeding studies. Direct estimates and bioenergetics model estimates of daily food consumption in the culture ponds were in poor agreement and the discrepancy varied with respect to walleye size. Food consumption rates in the ponds were related to walleye size (direct estimates) or water temperature (bioenergetics model estimates) but not zooplankton abundance. Growth exceeded 0.10 g g−1 d−1 for all but one sampling interval and the maximum growth rate in the culture pond fish was double the maximum growth rate determined in the laboratory. Growth was positively related to pond temperature and negatively related to walleye mass, but was not significantly related to zooplankton abundance. Gross conversion efficiency was negatively related to walleye mass, positively related to zooplankton abundance and not related to temperature. Food consumption and growth of walleye larvae in the field may be food-limited at much lower prey abundances than previous laboratory research has suggested.
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    URL: http://dx.doi.org/10.1023/A:1003755115000
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    Biota contamination by PCBs and trace metals in the freshwater estuary of the River Seine (France) (1999)
    Springer
    Hydrobiologia 400 (1999), S. 149-154 
    Details
    ISSN: 1573-5117
    Keywords: polychlorobiphenyls ; trace metals ; fish ; Seine estuary
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We studied the impact of urban and industrial activity upon the occurrence and the distribution of pollutants in the fresh estuary of the River Seine. Contamination was investigated under dry weather conditions, by determination of PCB and trace metal levels upstream and downstream of Rouen and the pollutant content of organisms with different positions in the trophic web. PCB contents of roach were higher downstream than upstream of Rouen. Cd levels showed a regular four fold increase from upstream to downstream of Rouen. Cyprinidae (ablet, roach) showed similar PCB or even higher trace metal levels than their predators (Percidae). This result suggests that contaminated food intake was not the main pathway for pollutant accumulation.
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    Modelling the ecological aspects of bankside reservoirs and implications for management (1999)
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    Hydrobiologia 395-396 (1999), S. 133-147 
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    ISSN: 1573-5117
    Keywords: reservoir ; quality management ; modelling ; algae ; zooplankton ; fish
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Bankside storage reservoirs are used as a major water supply resource in the lower Thames Valley, England. They form the link between the River Thames and the water treatment works of the Greater London area. The reservoirs act as both a water reserve in times of low river flows, and a quality ‘buffer’ between the river and the treatment works. The load on the water treatment works (particulate material, physico-chemical characteristics) primarily reflects the water qualities of the reservoirs. Management of such reservoirs thus seeks to reduce the adverse impacts which would otherwise arise from direct river use, and to ensure as far as possible that the ecological processes within the reservoirs do not introduce new challenges to the water treatment. Reservoir management clearly needs a good understanding of those ecological processes and their interactions, and, hopefully, a means to exploit that understanding in hindcasting to explain past events, in forecasting near- or far-future events, and to help in exploring operational options to ameliorate any foreseable difficulties. The reservoirs consist of a variety of configurations, physical dimensions and operational circumstances. They have, importantly, basically simple morphologies, known hydraulic regimes and physico-chemical qualities. Nonetheless, they appear to behave essentially as small (1–50 Mm3), eutrophic lakes; and various aspects of their ecology has been studied for the past 65 years. Their attributes and operational involvement make them ideal candidates for ecological modelling, which has been applied to them in varying extents for the past 30 years. The major conclusion which may be drawn from these studies is that even in such relatively simple water bodies, current (and probably future) models can only encompass their broad ecological characteristics. Detailed operational needs have to be met by a variety of modelling approaches, mainly predicated on the basis of only being able to know a lot about a little or a little about a lot. The operational needs for modelling fall into the following broad types: (a) understanding: why did those events occur, or where is our ignorance greatest? (b) short-term forecasts: how will the current situation develop in the short-term (weeks)? (c) what-if considerations: what would happen if some management facility were employed or used differently? (d) optimisation: what are the optimal volume– quality supply arrangements? (e) long-term prediction: what is the longer-term (years) outlook under foreseeable scenarios? (f) projective evaluation: how would potential, as yet non-existant reservoirs behave under prescribed circumstances? Examples of how these needs have been met are outlined, with examples ranging from simple models of the diatom ecology of the reservoirs to much broader trophic–dynamic descriptions which can allow expression of fish–zooplankton–phytoplankton interactions. This is crucial for present and future management of cyanobacterial phases. It is clear that considerable management insight and control can result from modelling assistance, but only if the appropriate questions are asked. Whilst simple short-term modelling is less demanding, any attempt to model the full complexity of the ecology of even these relatively simple water-bodies is probably doomed to founder on complexity–understanding difficulties, unless these are resolved to much more constrained system aspects. This is particularly so for the qualitative biology. The best that may presently be foreseen is for development of the newer multi-biological type models, with reasonably realistic and dynamic physical and chemical environment sub-models, being able to manifest the general characteristics of the ecosystem in question. Despite such difficulties, new reservoir management insights and approaches will inevitably be founded on critical modelling of those ecosystems.
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    The Bioaccumulation of Mercury in Aquatic Organisms from Two Similar Lakes with Differing pH (1999)
    Springer
    Ecotoxicology 8 (1999), S. 49-56 
    Details
    ISSN: 1573-3017
    Keywords: mercury ; methylmercury ; fish ; acidification ; biomagnification
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Two small drainage lakes of similar surface area (0.4–0.6 km 2 ) and depth, and situated in close proximity to one another (about 9 km apart) in the Muskoka-Haliburton district of rural Ontario, Canada were chosen to investigate the effects of differing pH on Hg accumulation in fish and other biota. Blue Chalk Lake is circumneutral (pH = 6.3–6.9) with an average dissolved organic carbon (DOC) concentration of 2.69 mg/L; Plastic Lake is acidic (pH = 5.2–5.6) with a similar DOC level (2.72 mg/L). Neither lake is an impoundment, and neither receives inputs from point-source urban or industrial waste emissions. Surficial (top 4 cm) sediments and various aquatic biota, including crayfish (Orconectes virilis)], and 5 species of fish [brown bullhead (Ictalurus nebulosus), creek chub (Semotilus atromaculatus), pumpkinseed sunfish (Lepomis gibbosus), yellow perch (Perca flavenscens) and rock bass (Ambloplites rupestris)] were sampled for Hg analysis. Only creek chub and pumpkinseed occurred in both lakes. Significant size (length) vs. Hg-concentration relationships were observed for brown bullhead, pumpkinseed, yellow perch and rock bass, but not for crayfish nor for creek chub in either lake. Rock bass had the highest mean Hg concentration (1.02 ± 0.98 μg/g dry wt.). Pumpkinseed from Plastic Lake had the highest overall rate of accumulation with increasing size. Several individual pumpkinseed and rock bass sampled from the acidic Plastic Lake had Hg concentrations equal to or greater than levels reported to be hazardous to breeding piscivorous birds, such as common loons (Gavia immer), whereas no fish from Blue Chalk approached this threshold (0.3 μg/g wet wt). This study illustrates the importance of within-lake parameters, particularly pH, and species trophic level, in determining Hg accumulation in fish in lakes of similar size that receive similar atmospheric Hg inputs.
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    Rubidium and Cesium Kinetics and Tissue Distributions in Channel Catfish (Ictalurus punctatus) (1999)
    Springer
    Ecotoxicology 8 (1999), S. 287-300 
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    ISSN: 1573-3017
    Keywords: rubidium ; cesium ; kinetics ; clearance-volume model ; fish
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract We used a two-compartment, clearance volume-based model to examine rubidium and cesium pharmacokinetics in channel catfish (Ictalurus punctatus) after intravascular administration. We compared the apparent volumes of distribution in the central and peripheral compartments and the intercompartmental and whole-body clearances of both metals at 20.0 °C and 27.5 °C. Biological half-times of Rb were 15 to 16 d at both temperatures, but Cs biological half-times averaged 101 d and 85 d at 20.0 °C and 27.5 °C, respectively (5 to 7 times longer than those of Rb in the same individual). Both the intercompartmental and total body clearances of Rb were also 6 to 7 times greater than those of Cs. The apparent volumes of distribution for Rb in the central compartments were twice those of Cs and remained constant with temperature. The apparent volumes of distribution of both elements in peripheral compartments were large compared with their corresponding central compartments, and decreased by a similar extent with increased temperature. Cesium tissue to blood ratios were greatest for white muscle, with more than 85% of the Cs present in this tissue. Partitioning of Cs in peripheral tissues apparently decreased with increased temperature conditions. Our results indicate that application of pharmacokinetic modeling techniques can enhance studies of radionuclide kinetics by helping to identify rate-limiting processes within individuals that may control uptake and elimination.
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    An Oxidative Mechanism for the Inhibition of Iodothyronine 5′-Monodeiodinase Activity by Lead Nitrate in the Fish, Heteropneustes fossilis (1999)
    Springer
    Water, air & soil pollution 111 (1999), S. 417-423 
    Details
    ISSN: 1573-2932
    Keywords: antioxidant enzymes ; fish ; iodothyronine 5′-monodeiodinase ; lead ; lipid peroxidation ; thyroid hormones
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract An oxidative mechanism in the lead-induced inhibition of thyroid function with special reference to iodothyronine 5′- monodeiodinase (5′-ID) activity has been identified in the fish, Heteropneustes fossilis. Lead treatment (2.5, 5.0 and 10.0 ppm of lead nitrate/day for 30 days) enhanced tissue lipid peroxidation (LPO) and decreased the activity of antioxidant enzymes such as superoxide dismutase (SOD) and catalase (CAT). In addition, serum triiodothyronine (T3) concentration and hepatic 5'-ID activity were markedly decreased by 10 ppm of lead nitrate. These findings support the view that higher concentrations of lead nitrate inhibit the extrathyroidal conversion of thyroxine (T4) to T3. Moreover, oxidative stress from lead intoxication could be responsible for inhibiting 5′-ID activity.
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    What is a fish species? (1999)
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    Reviews in fish biology and fisheries 9 (1999), S. 281-297 
    Details
    ISSN: 1573-5184
    Keywords: fish ; gene flow ; hybridization ; molecular phylogenetics ; speciation ; species concepts
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The formal processes of alpha-taxonomy ensure that species have uniquenames and can be identified. No similar process is mandatory forinfraspecific variation, so the species is a uniquely importantpractical term. At present, there is little agreement of the definitionof a species. In the last 30 years, numerous concepts have beenproposed. The nature of fish species is reviewed. Clonal inheritance ofnuclear genes occurs in several lineages. Hybridization is frequent,often leading to introgression, which may lead to extinction of species.Species may have hybrid origins. There is good evidence for parallelspeciation in similar habitats. There are clearly exceptions to thecladistic assumption of dichotomous branching during speciation. Siblingspecies may exist with no discernible niche differentiation. Basic assumptions are violated for the recognition, phylogenetic,ecological and some formulations of the evolutionary species concepts.The most satisfactory definitions are two of the earliest proposed inthe light of evolutionary theory. The Darwinian view is that species arerecognizable entities which are not qualitatively distinct fromvarieties. A restatement of this concept in genetic terms provides ameans of dealing with all forms of species known in present-day fishes.This modified Darwinian concept is operated through the application offuzzy logic rather than rigid definition. This involves a search fordiscontinuities between species, rather than an a priori definition ofhow boundaries are to be determined. A subset of Darwinian species areMayrian or ‘biological species’, which are characterized by theirdemonstrable reproductive isolation from other species. The status of apopulation as a Mayrian species is a testable hypothesis. Moleculartechniques allow this hypothesis to be tested more easily thanpreviously, at least when dealing with sympatric populations.
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    Molecular markers and the species concept: New techniques to resolve old disputes? (1999)
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    Reviews in fish biology and fisheries 9 (1999), S. 379-382 
    Details
    ISSN: 1573-5184
    Keywords: fish ; molecular marker ; speciation ; species concept
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
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    URL: http://dx.doi.org/10.1023/A:1008967532146
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    Alloparental care in fishes (1999)
    Springer
    Reviews in fish biology and fisheries 9 (1999), S. 45-70 
    Details
    ISSN: 1573-5184
    Keywords: adoption ; alloparental care ; brood parasitism ; fish ; mutualism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Alloparental care, care directed at non-descendant young, presents a potential challenge to evolutionary ecologists because investment in non-descendant eggs and young gives the appearance of maladaptive behaviour. Yet wherever there is parental care in fishes, there is usually alloparental care. As such, alloparental care is an integral part of care in fishes. Alloparental care appears to have arisen independently many times in disparate taxa. The chief reason for this is the low cost of care, relative to homeotherms, both in terms of low post-zygotic investment to nourish young, and low risk of predation to the parent during brood defence. In some cases, alloparenting is misdirected parental care and maladaptive. A celebrated example of brood parasitism in fish is that of the catfish Synodontis multipunctatus, which parasitizes broods of mouthbrooding cichlids. Previously unpublished data on the reproductive biology of S. multipunctatus are reported here. However, in the majority of cases, particularly for the widespread phenomena of zygote dumping (nest associates) in the Cyprinidae and adoption of non-descendant free-swimming young in brood-guarding Cichlidae, alloparental care is a mutualistic relationship maintained by natural selection. This review describes broad patterns of known examples of alloparental care, the pathways to adoption, and highlights the ways in which alloparents derive fitness benefits. By caring for non-descendant young, an alloparent may benefit by one or more of the following phenomena: acquisition of mates, confusion effect, dilution effect, selfish herd effect, selfish shepherd effect, kin selection, and reciprocal altruism. Although the breadth and diversity of examples of alloparental care in fishes is growing, to date, these accounts have been largely descriptive. Future research should be directed at careful documentation of the fitness consequences for both donor and alloparent. These are the data that are needed to fully understand the evolutionary underpinnings of alloparental care, and by extension, parental care.
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    Interspecific variation in sustained swimming ability of late pelagic stage reef fish from two families (Pomacentridae and Chaetodontidae) (1998)
    Springer
    Coral reefs 17 (1998), S. 111-119 
    Details
    ISSN: 1432-0975
    Keywords: Key words Dispersal ; coral reefs ; fish ; swimming ; Larvae ; Juveniles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences
    Notes: Abstract  Characteristics of the pelagic stages of reef fishes have generally been investigated at the family level, which may mask important differences among species. Here the variation in sustained swimming ability of the late pelagic stages is examined among species, within two families (Pomacentridae and Chaetodontidae). The pomacentrids displayed a 7.5-fold difference in sustained swimming ability across 24 species, while the chaetodontids displayed a 2-fold difference across 10 species. The variation within the Pomacentridae was not related to pelagic larval duration, post-settlement habitat or taxonomy. There was, however, a significant correlation between sustained swimming ability and total length (TL) of individuals (r=0.435, P〈0.0001). Differences in the mean distance swum by pomacentrid species, however, was most strongly related to differences in mean wet weight (r=0.814, P〈0.0001). When the mean distance swum by species was scaled with respect to mean TL there was still a strong correlation with mean wet weight (r=0.644, P〈0.005). Among chaetodontid individuals TL and sustained swimming ability were not correlated (r=−0.004, P=0.978). Furthermore, sustained swimming ability was not significantly related to the trans-oceanic distribution of species in either family. The variation in sustained swimming ability, however, may contribute to explanations of the observed levels of gene flow within populations.
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    Estuarine reconnection of an impounded mangrove salt marsh in the Indian River Lagoon, Florida: short-term changes in fish fauna (1998)
    Springer
    Mangroves and salt marshes 2 (1998), S. 29-36 
    Details
    ISSN: 1572-977X
    Keywords: culverts ; culvert trap ; mosquito impoundment ; seine ; fish
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Fish population dynamics in a 24.3 ha mangrove-dominated mosquito impoundment in east-central Florida were examined by seining and culvert traps before and after installation of culverts that established estuarine connection for the first time in 39 years. In a 27-day period following the culvert opening, fish species increased from 9 to 21, while total number of fish in the impoundment decreased. Movement of fishes through culverts in both directions commenced immediately following culvert opening. Recruitment of transient species into the impoundment appeared to key on a single wind-driven high tide event. Such short-term events may be important cues for fish movement into and out of impounded salt marshes.
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    Structural organization of rat CD1 typifies evolutionarily conserved CD1D class genes (1998)
    Springer
    Immunogenetics 48 (1998), S. 22-31 
    Details
    ISSN: 1432-1211
    Keywords: Key words CD1 ; Rat ; Gene ; Organization ; Polymorphism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  The non-major histocompatibility complex (MHC)-encoded CD1 family has recently emerged as a new antigen-presenting system that is distinct from either MHC class I or class II molecules. In the present study, we determined the genomic structure of the rat CD1 locus. It was extremely similar to mouse CD1 genes, especially to CD1D1. The 5′ flanking region of the CD1 gene contained the binding motifs for two cytokine-inducible transcription factors, NF-IL2-A and NF-IL6. Some regulatory elements found in MHC class I genes (enhancer A, enhancer B, and the IFN response element) were absent. It is of interest that a tyrosine-based motif for endosomal localization found in the human CD1b cytoplasmic tail was encoded by a single short exon which was conserved in all CD1 molecules except for CD1a. Southern blot and direct sequencing analyses of inbred rat strains suggested very limited polymorphism in the 5′ region where a hydrophobic ligand-binding groove is encoded; a single base substitution resulted in amino acid alteration of alanine (GCT) to valine (GTT) at codon 119. Comparison of the overall exon-intron organization of CD1 genes revealed that the length of the intron was also characteristic to each of the two classes of CD1 genes, classic CD1 and CD1D; such categorization has hitherto been made according to the sequence similarity of the coding region. This finding provides further support for the hypothesis that the two classes have different evolutionary histories. In contrast to the complete absence of the classic CD1 in rats and mice, the entire region of nonpolymorphic CD1D has been conserved through mammalian evolution. Similar functional properties of rodent CD1 and human CD1d are implied.
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    URL: http://dx.doi.org/10.1007/s002510050396
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    Structural organization, sequence analysis, and physical mapping of the Grc-linked class Ib gene RT1.S3 in the rat (1998)
    Springer
    Immunogenetics 48 (1998), S. 76-81 
    Details
    ISSN: 1432-1211
    Keywords: Key words RT1.S3 ; Grc ; MHC ; Class I ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
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    URL: http://dx.doi.org/10.1007/s002510050405
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    Effects of space flight on GLUT-4 content in rat plantaris muscle (1998)
    Springer
    International journal of biometeorology 41 (1998), S. 101-104 
    Details
    ISSN: 1432-1254
    Keywords: Key words Space flight ; Rat ; Plantaris muscle ; GLUT-4 ; Citrate synthase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geography , Physics
    Notes: Abstract  The effects of 14 days of space flight on the glucose transporter protein (GLUT-4) were studied in the plantaris muscle of growing 9-week-old, male Sprague Dawley rats. The rats were randomly separated into five groups: pre-flight vivarium ground controls (PF-VC) sacrificed approximately 2 h after launch; flight groups sacrificed either approximately 5 h (F-R0) or 9 days (F-R9) after the return from space; and synchronous ground controls (SC-R0 and SC-R9) sacrificed at the same time as the respective flight groups. The flight groups F-R0 and F-R9 were exposed to micro-gravity for 14 days in the Spacelab module located in the cargo bay of the shuttle transport system – 58 of the manned Space Shuttle for the NASA mission named ”Spacelab Life Sciences 2”. Body weight and plantaris weight of SC-R0 and F-R0 were significantly higher than those of PF-VC. Neither body weight nor plantaris muscle weight in either group had changed 9 days after the return from space. As a result, body weight and plantaris muscle weight did not differ between the flight and synchronous control groups at any of the time points investigated. The GLUT-4 content (cpm/µg membrane protein) in the plantaris muscle did not show any significant change in response to 14 days of space flight or 9 days after return. Similarly, citrate synthase activity did not change during the course of the space flight or the recovery period. These results suggest that 14 days of space flight does not affect muscle mass or GLUT-4 content of the fast-twitch plantaris muscle in the rat.
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    Allozymes Reflect the Population-Level Effect of Mercury: Simulations of the Mosquitofish (Gambusia holbrooki Girard) GPI-2 Response (1998)
    Springer
    Ecotoxicology 7 (1998), S. 141-150 
    Details
    ISSN: 1573-3017
    Keywords: fish ; mercury ; natural selection ; allozyme ; population
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Measurements of the differential tolerance between enzyme genotypes and shifts in allozyme frequencies in populations from contaminated habitats have prompted the use of allozymes as markers of population-level toxicant effects. However, such studies often do not consider other factors that influence allele frequencies, including natural clines, migration, the intensity and specificity of selection and toxicant-induced genetic bottlenecks. In addition, selection components other than survival are not included. Consequently, the associated conclusions remain speculative. To assess this approach rigorously, a simulation study was conducted with the mosquitofish (Gambusia holbrooki) GPI-2 locus. Laboratory studies have shown the GPI-238/38 homozygote at this locus to be less tolerant than other genotypes during acute exposure to mercury. The GPI-2100/100 genotype has also been shown to have a reproductive disadvantage at lower mercury concentrations. Simple and then more complex models were used to quantify the relative effects of viability selection, random genetic drift and migration on the GPI-238 allele frequency. Simulations were also performed to assess the contribution of sexual and fecundity selection. A simple population model suggested that viability selection plays a greater role than does mortality-driven, genetic drift in the decrease of the sensitive allele under the conditions of this study. A more complex, stochastic model indicated that no significant mortality-driven drift was taking place in this system. In both models, migration mitigated the effect of selection. Sexual and fecundity selection had little effect on the allele frequencies in these simulations. We conclude that, provided the system under study is clearly understood, shifts in allele frequency can indicate the population-level effects of pollutants.
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    URL: http://dx.doi.org/10.1023/A:1014352226686
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    Flow Cytometric Analysis of Erythrocyte and Leukocyte DNA in Fish from Chernobyl-Contaminated ponds in the Ukraine (1998)
    Springer
    Ecotoxicology 7 (1998), S. 211-219 
    Details
    ISSN: 1573-3017
    Keywords: genotoxicity ; Chernobyl ; fish ; flow cytometry ; coefficient of variation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Flow cytometric (FCM) analysis was used to assess the potential impact of chronic radionuclide exposure in fish populations inhabiting contaminated sites in the vicinity of the Chernobyl nuclear accident. Four species of fish, channel catfish (Ictalurus punctatus), crucian carp (Carassius carassius), carp (Cyprinus carpio) and tench (Tinca tinca), were collected within a 10 km radius of the Chernobyl Nuclear Power Plant and compared with 'control' populations from two uncontaminated locations far removed from the plant. Assays of whole blood, as well as separate erythrocyte and leukocyte components, revealed aneuploid-like patterns in the DNA histograms of some fish, as well as widened G0/G1 peaks. None of the fish collected from the uncontaminated sites demonstrated these kinds of changes in their DNA histograms. Increases in the coefficient of variation (CV) of the G0/G1 peak, indicating abnormal DNA distributions, were observed in several of the fish from Chernobyl relative to the control populations. Cell cycle perturbation in fish from the contaminated sites was also detected, with a higher percentage of cells in G2/M phase relative to the controls. Leukocytes proved more sensitive than erythrocytes, as they displayed a larger number of abnormal DNA histograms. Variations in the cellular DNA content similar to those reported here have been shown for other vertebrate species exposed to radiation and other genotoxic agents in laboratory and field settings.
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    Influence of Taxonomy, Ecology, and Seasonality in River Stage on Fish Contamination Risks in Floodplain Swamps of the Lower Mississippi River (1998)
    Springer
    Ecotoxicology 7 (1998), S. 325-334 
    Details
    ISSN: 1573-3017
    Keywords: contamination risks ; fish ; Mississippi River ; ecological factors ; taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract We compared contamination levels in fish from contaminated and uncontaminated floodplain swamps of the lower Mississippi River to assess differences in contamination risks between swamps, across different taxonomic and ecological groupings of fishes within and between swamps, and with seasonality in river stage. Fish tissue levels of inorganic contaminants were substantially lower than environmental levels in both swamps, suggesting either that fish were not uptaking these contaminants, or they were effectively eliminating the contaminants from their bodies. Tissue levels of organic contaminants were high relative to environmental levels, suggesting that these contaminants were bioaccumulating. Organic contaminants were significantly higher in fish from the contaminated swamp (Devil's Swamp) than in fish from a reference swamp up river (Tunica Swamp). Because the organic contaminants were largely confined to sediments, we expected bottom-oriented fishes to have higher concentrations than pelagic fishes. Assuming that uptake was primarily through the food chain, we expected top predators to exhibit higher concentrations than low-level consumers. We also expected year- round swamp residents to exhibit higher accumulations than more transitory users of backswamp habitat. However, organic contaminant levels did not differ in the directions expected for any of these groupings. We did observe differences in organic contaminant levels within and between swamps for different taxonomic groupings of fishes (species and genera). Some taxa occupying low to middle positions in the food web (e.g., gizzard shad, Lepomis spp.) exhibited higher concentrations than taxa near the top of the food web. Within Devil's Swamp, organic contaminant levels were significantly higher at low river stage, when fish were confined to the swamp, than at high river stage, when fish were free to move between the river and the swamp. We caught more species and more fish per unit effort in Devil's Swamp than in Tunica Swamp, contrary to expectations if contaminants in the former were negatively impacting population and community structure. Species richness differences between swamps were a consequence of catch differences, with higher catch corresponding to inclusion of more rare species. The lower catch in Tunica Swamp may have resulted from physical modifications of its waterways to support agriculture and hunting. The results of this study underscore the importance in factoring information on the taxonomy and ecology of organisms, and seasonal changes in environmental conditions, into assessments of contamination risks.
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    N18-RE-105 cells: differentiation and activation of p53 in response to glutamate and adriamycin is blocked by SV40 large T antigen tsA58 (1998)
    Springer
    Cell & tissue research 291 (1998), S. 191-205 
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    ISSN: 1432-0878
    Keywords: Key words N18-RE-105 cells ; Glutamate ; p53 ; Adriamycin ; Etoposide ; Differentiation ; SV40 large T antigen ; Mouse ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Process extension was induced in cells of the N18-RE-105 neuroblastoma-retinal hybrid line by toxic agents, including glutamate and the p53-inducing anticancer agents adriamycin and etoposide. Both adriamycin and glutamate activated p53 as measured by a plasmid transfection assay. It was therefore hypothesized that SV40 large T antigen, which binds p53, would interfere with cellular differentiation. To test this hypothesis, the temperature-sensitive form of SV40 large T was transduced into N18-RE-105 cells by retroviral infection. SV40 large T-infected cells became de-differentiated, grew in tightly-packed colonies, lost expression of neurofilament, and lost the ability to differentiate in response to glutamate and adriamycin. The de-differentiating effect of SV40 large T antigen may be due to binding and inactivation of cellular proteins, such as p53, p107, p130, p300, and retinoblastoma protein, which are important in cellular growth and differentiation. It is suggested that p53 may play a role in cellular differentiation, perhaps under unusual circumstances involving stress or cytotoxicity.
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    Localization of elastin mRNA and TGF-β1 in rat aorta and caudal artery as a function of age (1998)
    Springer
    Cell & tissue research 291 (1998), S. 305-314 
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    ISSN: 1432-0878
    Keywords: Key words Elastin ; TGF-β1 ; Arteries ; In situ hybridization ; Immunohistochemistry ; Northern blot ; Ageing ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Several in vitro studies have previously demonstrated that the addition of TGF-β to aortic smooth muscle cells or skin fibroblasts stimulates elastin synthesis. It is not clear however whether, in vivo, TGF-β participates in the regulation of elastin synthesis, especially in physiological conditions. The aim of our study was to explore the localization of elastin mRNA and TGF-β1 in the rat thoracic aorta (an elastic artery) and caudal artery (a muscular artery). Elastin mRNA was localized by in situ hybridization and quantified using Northern blot analysis. TGF-β1 was detected using immunohistochemistry. The study was carried out as a function of age (rats of 3, 10, 20, and 30 months). We observed that TGF-β1 immunoreactivity is present predominantly, but not exclusively, at the sites of elastin synthesis as determined by elastin mRNA detection: in smooth muscle cells in the aorta and in endothelial cells in the caudal artery. The ability of exogenously added TGF-β1 (0.001–10 ng/ml) to modulate the steady-state levels of elastin mRNA in primary cultures of endothelial cells, smooth muscle cells, and fibroblasts isolated from the thoracic aorta was also studied. At the highest concentration used, elastin mRNA levels increased 5-fold in endothelial cells and 11-fold in smooth muscle cells. The demonstration that TGF-β1 immunoreactivity is present at the sites of elastin synthesis in the thoracic aorta and in the caudal artery and the observation that TGF-β1 induces an increase in elastin mRNA levels in cultured endothelial cells and smooth muscle cells suggest that TGF-β1 may be implicated, at least in part, in the physiological regulation of elastin gene expression.
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    A culture substratum appropriate for brain cells is a chondroitin sulfate glycosaminoglycan in serum (1998)
    Springer
    Cell & tissue research 291 (1998), S. 445-454 
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    ISSN: 1432-0878
    Keywords: Key words Serum-free medium ; Survival ; Chondroitin sulfate ; Culture substratum ; Brain neuron ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  When cells dissociated from the neonatal rat brains are plated on a poly-lysine-coated surface in a serum-free medium, they display a strange morphology: a dark and extended cell body. Preincubation of the surface with fetal bovine serum was found to inhibit the appearance of this strange contraction of the basal cell sheets in a dose-dependent manner. This finding indicated the presence of a factor(s) in the serum, which might be an appropriate substratum for prolonged survival of brain neurons. In the current study, this factor was highly purified through DEAE ion-exchange chromatography followed by gel filtration. The factor was eluted from a Superose column at fractions corresponding to a molecular weight greater than 1000 kDa. By SDS-PAGE analysis, these fractions were found to contain a major band (≥1000 kDa) positive for alcian blue and few minor bands faintly stainable with Coomassie blue. The activity of the purified sample, inducing the morphological change in cells, was diminished by incubation with chondroitinase ABC. Neither heparitinase II, hyaluronidase, nor trypsin modified the activity. An authentic chondroitin sulfate (type B) mimicked the serum action on the morphology of brain cells in early stages of culture. Taking these findings together, it is suggested that the factor in serum beneficial for the attachment of brain cells is composed of a chondroitin sulfate with a Mr greater than 1000 kDa. Cortical cells dissociated from the neonatal rat brain attached well to the purified factor-coated surface and displayed a healthy morphology: an optically-reflective cell body with thick neurites for at least 3 days in the absence of serum.
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    Double-labeling techniques demonstrate that rod bipolar cells are under GABAergic control in the inner plexiform layer of the rat retina (1998)
    Springer
    Cell & tissue research 292 (1998), S. 17-25 
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    ISSN: 1432-0878
    Keywords: Key words Retina ; Rod bipolar cells ; Amacrine cells ; Protein kinase C ; Glutamic acid decarboxylase ; GABA ; Synaptic circuitry ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  The synaptic connectivity between rod bipolar cells and GABAergic neurons in the inner plexiform layer (IPL) of the rat retina was studied using two immunocytochemical markers. Rod bipolar cells were stained with an antibody specific for protein kinase C (PKC, α isoenzyme), and GABAergic neurons were stained with an antiserum specific for glutamic-acid decarboxylase (GAD). Some amacrine cells were also labeled with the anti-PKC antiserum. All PKC-labeled amacrine cells examined showed GABA immunoreactivity, indicating that PKC-labeled amacrine cells constitute a subpopulation of GABAergic amacrine cells in the rat retina. A total of 150 ribbon synapses established by rod bipolar cells were observed in the IPL. One member of the postsynaptic dyads was always an unlabeled AII amacrine cell process, and the other belonged to an amacrine-cell process showing GAD immunoreactivity. The majority (n=92) (61.3%) of these processes made reciprocal synapses back to the axon terminals of rod bipolar cells. In addition, 78 conventional synapses onto rod bipolar axons were observed, and among them 52 (66.7%) were GAD-immunoreactive. Thus GABA provides the major inhibitory input to rod bipolar cells.
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    Neuronal differentiation is accompanied by NSP-C expression (1998)
    Springer
    Cell & tissue research 292 (1998), S. 229-237 
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    ISSN: 1432-0878
    Keywords: Key words PC12 ; hNT2 ; Neuroblastoma cell lines ; NGF ; Retinoic acid ; Rat ; Human cell lines
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Neuroendocrine-specific protein (NSP) reticulons are expressed in neural and neuroendocrine tissues and cell cultures derived therefrom, while most other cell types lack NSP-reticulons. Three major subtypes have been identified so far, designated NSP-A, NSP-B, and NSP-C. We have investigated the correlation between the degree of neuronal differentiation, determined by morphological and biochemical criteria, and NSP-reticulon subtype expression. For this purpose, several human neuroblastoma cell lines, exhibiting different degrees of neuronal differentiation, were examined immuno(cyto) chemically. It became obvious that the expression of NSP-C, as detected by immunofluorescence microscopy and Western blotting, is most prominent in cell lines with a high degree of neuronal differentiation, such as LA-N-5. Such highly differentiated cells also express other neural and neuroendocrine markers, such as neural cell adhesion molecule (NCAM), neurofilament proteins, synaptophysin, and chromogranin. NSP-A was observed in all cell lines to a different extent. However, no clear correlation was observed with the degree of neuronal differentiation as defined by other neuronal and neuroendocrine markers or morphology. NSP-B could not be detected. The induction of neuronal differentiation with nerve growth factor, dbcAMP, and retinoic acid in the rat pheochromocytoma cell line PC12 and the human teratocarcinoma cell line hNT2, respectively, induced the expression of NSP-A and NSP-C in these cell lines parallel to the induction of neurofilament protein expression. It is concluded that NSP-C expression, in particular, is strongly correlated with neuronal differentiation.
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    Light- and electron-microscopic study of the distribution of axons containing substance P and the localization of neurokinin-1 receptor in bone (1998)
    Springer
    Cell & tissue research 293 (1998), S. 87-93 
    Details
    ISSN: 1432-0878
    Keywords: Key words Osteoclasts ; Osteoblasts ; Osteocytes ; Bone ; Substance P (SP) ; Neurokinin-1 receptor (NK1-R) ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Substance P (SP) is a neuropeptide that is released from axons of sensory neurons and causes signal transduction through the activation of the neurokinin-1 receptor (NK1-R). The present study demonstrates the distribution of SP-like-immunoreactive (SP-LI) axons and the localization of NK1-Rs in rat bone tissue using the avidin-biotin-peroxidase complex method. Axons with SP-LI were commonly found near the trabecular bone in the temporal bone marrow, but they were only sparsely distributed in the mandible, femur, and tibia. Immunoreactivity for NK1-Rs was found on the plasma membrane and in the cytoplasm of the osteoclasts. In the osteoblasts and osteocytes, a small number of weak, punctate immunoreactive products of NK1-Rs were distributed close to the plasma membrane. At the electron-microscopic level, immunoreactivity for NK1-R was distributed mainly in the whole cytoplasm, except for the clear zone of the osteoclasts, and in pit-like structures along the plasma membrane. The NK1-R-immunoreactive structures in the cytoplasm were divided into two types of organelles, consisting of vesicular and vacuolar structures (probably transport vesicles and early endosomes). In the osteoblasts and osteocytes, the number of NK1-R-positive vesicular structures was fewer than in the osteoclasts. These results thus suggest that SP secreted by the sensory axons could directly modulate bone metabolism via NK1-Rs.
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    The internal and external protein scaffold of the T-tubular system in cardiomyocytes (1998)
    Springer
    Cell & tissue research 294 (1998), S. 449-460 
    Details
    ISSN: 1432-0878
    Keywords: Key words Vinculin ; Talin ; Integrin ; Dystrophin ; Spectrin ; T-tubule ; Costamere ; Basal membrane ; Cardiac muscle cell ; Dilated cardiomyopathy ; Human ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The transverse tubule system of the cardiomyocyte remains undeformed despite the extreme forces it undergoes during the contraction-relaxation cycle, but the morphological basis for its stability remains unclear. Therefore, we have investigated the architecture and subcellular protein scaffold of the cardiac T-tubules and compared it with that of the costameres and of the free sarcolemma. Tissue samples from normal rat and monkey hearts, and left ventricular tissue from normal and cardiomyopathic human hearts obtained at transplantation surgery were investigated using immunocytochemistry and confocal microscopy and by electron microscopy. In addition, we used a re-differentiation model of isolated, cultured adult rat cardiomyocytes. The cell membrane of the cardiac T-tubules was found to contain the cell-matrix focal adhesion molecules (FAMs) vinculin, talin, the α5β1 integrin and the membrane-associated proteins (MAPs) dystrophin and spectrin. FAMs and MAPs were localized in the T-tubular membrane in a similar pattern: in longitudinally oriented myocytes as transverse punctate lines at the Z-level; in transversally cut myocytes a radial tubular network was found to extend throughout the interior of the cell. Immunolabeling for basement membrane components including collagen IV, fibronectin and laminin showed a colocalization with FAMs and MAPs parallel to the transverse T-tubules. The costameres of the sarcolemma showed a protein composition resembling that of the T-tubules but the intervening segments of free sarcolemma showed absence of FAMs and presence of MAPs. For the first time, we demonstrate the existence and protein composition of the T-tubular scaffold in the human heart. Furthermore, we show that cardiomyocytes from human failing hearts have less abundant but more dilated T-tubules than do experimental animals. These results indicate that the cardiac T-tubular system contains a subcellular scaffold closely resembling that of the costameres. It consists of FAMs, MAPs and basal lamina proteins that confer structural integrity to the cardiac T-tubular membrane during contraction/relaxation cycles.
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    Chymotrypsin gene expression in rat peripheral organs (1998)
    Springer
    Cell & tissue research 292 (1998), S. 345-354 
    Details
    ISSN: 1432-0878
    Keywords: Key words Pancreas ; Stomach ; Duodenum ; Ribonuclease protection assay ; Immunocytochemistry ; Protease ; Rat ; (Sprague Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Prior studies have revealed the presence of chymotrypsinlike protease in peripheral organs, although no definitive evidence for the synthesis of this enzyme in tissue other than the pancreas is available. In an attempt to detect chymotrypsinogen mRNA in peripheral organs, a fragment of the pancreatic chymotrypsin mRNA from rat was amplified using PCR. The sequence was identified as a portion of the rat chymotrypsin B gene overlapping exon 5 through exon 7. It was subcloned into the pGEM-4Z vector and used as a template for the vitro transcription of an antisense riboprobe. Using ribonuclease protection and Northern blot analyses, chymotrypsin mRNA was detected in the rat pancreas, stomach, duodenum, ovary, and spleen. Monoclonal and polyclonal antisera against chymotrypsin detected chymotrypsinlike immunoreactivity in rat and human pancreas, rat stomach, duodenum and jejunum. Electrophoresis and immunoblotting revealed chymotrypsin-chymotrypsinogen bands (25–29 kDa) in the stomach and duodenum. Synthesis of a potent protease such as chymotrypsin in tissue other than pancreas is significant, suggesting a potential physiological and/or pathological role in these tissues.
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    Specific localization of gap junction protein, connexin45, in the deep muscular plexus of dog and rat small intestine (1998)
    Springer
    Cell & tissue research 292 (1998), S. 487-494 
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    ISSN: 1432-0878
    Keywords: Key words Connexin ; Gap junctions ; Smooth muscle ; Intestinal pacemaker ; Confocal laser scanning microscope ; Dog ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Cellular networks of pacemaker activity in intestinal movements are still a matter of debate. Because gap-junctional intercellular communication in the intestinal wall may provide important clues for understanding regulatory mechanisms of intestinal movements, we have attempted to clarify the distribution patterns of three types of gap junction proteins. Using antibodies for connexin40, connexin43, connexin45, smooth muscle actin, and vimentin, immunocytochemical observations were made with the confocal laser scanning microscope on cryosections of fresh-frozen small intestine and colon of the dog and rat. Connexin 45 was localized along the deep muscular plexus of the small intestine in both dog and rat. Double labeling studies revealed that connexin45 overlapped with vimentin –, but not actin-positive areas, indicating the fibroblast-like nature of the cells, rather than their being smooth muscle-like. Connexin43 immunoreactivity appeared along the smooth muscle cell surface in the outer circular layer of the small intestine of both animals. Connexin 40 immunoreactivity was not observed in the muscle layer other than in the wall of large blood vessels. It is suggested that connexin45-expressing cells along the deep muscular plexus of dog and rat small intestine are likely to act as a constituent of a pacemaker system, which may include a conductive system, by forming a cellular network operating via specific types of gap junctions.
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    Calretinin-immunoreactive laminar nerve endings in the laryngeal mucosa of the rat (1998)
    Springer
    Cell & tissue research 292 (1998), S. 613-617 
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    ISSN: 1432-0878
    Keywords: Key words Sensory nerve endings ; Calretinin ; Laryngeal mucosa ; Immunohistochemistry ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The distribution of laminar nerve endings that contained immunoreactive calretinin was examined in the laryngeal mucosa of the adult rat. In whole-mount preparations, the immunoreactive laminar endings were distributed in the supraglottic region but not in the subglottic region. The laminar endings that arose from thick nerve fibers with or without swellings were identified as corpuscles with many variform terminal arborizations. They appeared to be located at the interface between the epithelium and the subepithelial connective tissue. The terminals were scattered under the basal lamina of the epithelium, and some of them were located within the epithelial layer. Immunoelectron microscopy revealed that both sub- and intraepithelial immunoreactive terminals that were filled with mitochondria were partly or totally ensheathed by Schwann cell processes. The denervation experiments, in which the superior laryngeal nerve was cut unilaterally or bilaterally, suggested that the laminar endings originate from the superior laryngeal nerve with strict ipsilateral innervation. The laminar endings might be associated with detection of changes in pressure in the laryngeal cavity or chemical stimuli.
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    A novel type of adhering junction in an epithelioid tumorigenic rat cell culture line (1998)
    Springer
    Cell & tissue research 294 (1998), S. 11-25 
    Details
    ISSN: 1432-0878
    Keywords: Key words Adhering junctions ; Desmosomes ; Endothelial junctions ; Plaque proteins ; Desmoplakin ; Cadherins ; Protein ZO-1 ; Rat ; cell culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Two major types of plaque-bearing adhering junctions are commonly distinguished: the actin microfilament-anchoring adhaerens junctions (AJs) and the desmosomes anchoring intermediate-sized filaments (IFs). Both types of junction usually possess the common plaque protein, plakoglobin, whereas the other plaque proteins and the transmembrane cadherins are mutually exclusive. For example, AJs contain E-, N-, or P-cadherin in combination with α- and β-catenin, vinculin and α-actinin, whereas in desmosomes, desmogleins and desmocollins are associated with desmoplakin and one or several of the plakophilins (PP1–3). Here we describe a novel type of adhering junction comprising proteins of both AJs and desmosomes and the tight junction (TJ) plaque protein, ZO-1, in a newly established, liver-derived tumorigenic rat cell line (RMEC-1). By immunofluorescence microscopy, cell-cell contacts are characterized by mostly continuous-appearing lines which are usually resolved by electron microscopy as extended arrays of closely spaced small plaque subunits. These plaque-covered regions are positive for plakoglobin, α- and β-catenin, the arm-repeat protein p120, vinculin, desmoplakin and protein ZO-1. They are positive for E-cadherin in cultures early on in passaging, but tend to turn negative for all known cadherins in densely grown cultures. On immunoblotting SDS-PAGE-separated proteins from dense-grown cell monolayers, “pan-cadherin” antibodies have reacted with a band at ∼140 kDa, identified as N-cadherin by peptide fingerprinting of the immunoprecipitated protein, which for reasons not yet clear is modified or masked in immunolocalization experiments. The exact histological derivation of RMEC-1 cells is not known. However, the observations of several endothelial markers and the fact that all cells are rich in IFs containing vimentin and/or desmin, while only subpopulations also reveal IFs containing CKs 8 and 18, is suggestive of a mesenchymal, probably endothelial origin. We discuss the molecular relationship of this novel type of extended junction with other types of adhering junctions.
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    URL: http://dx.doi.org/10.1007/s004410051152
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    Effects of growth rate and cell density on nerve growth factor secretion in cultures of vascular and bladder smooth muscle cells from hypertensive and hyperactive rats (1998)
    Springer
    Cell & tissue research 294 (1998), S. 431-438 
    Details
    ISSN: 1432-0878
    Keywords: Key words Nerve growth factor ; Hypertension ; Contact inhibition ; Proliferation ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Elevated target-derived smooth muscle nerve growth factor (NGF) and resultant neurogenic plasticity are associated with both hypertension and hyperactive voiding in spontaneously hypertensive rats (SHRs: hypertensive, behaviorally hyperactive). In culture, vascular (VSMCs) and bladder (BSMCs) smooth muscle cells derived from SHRs secrete higher levels of NGF, proliferate more rapidly, and achieve higher density at confluence than do control Wistar-Kyoto (WKY) cells. To elucidate growth-related contributions to the elevated tissue NGF observed in SHRs, we examined vascular VSMC and BSMC NGF secretion in two inbred cell lines (WKHTs, hypertensive; WKHAs, hyperactive) derived from SHRs and WKYs to assess the phenotypic association of altered NGF metabolism with either hypertension or behavioral hyperactivity. Cell density, rather than growth rates, was the most important factor with respect to NGF secretion. VSMC density varied such that WKHT=SHR〉WKY= WKHA, higher VSMC density being associated with higher NGF output. However, in BSMC cultures, NGF output was the lowest in high density cell lines, with WKHT〉SHR〉WKY〉WKHA. SHR BSMCs had the second highest cell density and NGF secretion level. Elevated packing density, presumably because of a lack of contact inhibition, co-segregated with the hypertensive phenotype in both VSMCs and BSMCs. Thus, dysfunctional smooth muscle growth characteristics may contribute to the augmented vascular and bladder NGF content associated with high blood pressure and hyperactive voiding in SHRs.
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    URL: http://dx.doi.org/10.1007/s004410051194
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    Loss of myocardial capillary endothelial-cell alkaline phosphatase (ALP) activity in primary endothelial cell culture (1998)
    Springer
    Cell & tissue research 291 (1998), S. 497-505 
    Details
    ISSN: 1432-0878
    Keywords: Key words Endothelial cells ; Alkaline phophatase ; Primary cultures ; Proliferation ; Gene expression ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Primary cultures of rat myocardial capillary endothelial cells were established and characterized. A range of typical endothelial cell-specific markers were retained in vitro. Cell kinetic studies in confluent endothelial-cell cultures in vitro revealed a roughly 50-fold increase in the proportion of cells in s-phase, indicating a very considerable shortening of cell turnover time, compared to in vivo conditions. Alkaline phosphatase enzyme activity and encoding mRNA are strongly expressed in myocardial capillary endothelial cells in vivo, but were not detectable in vitro. This was true in cell cultures from two strains of rat, which revealed significantly different enzyme expression levels in vivo. In co-cultures of pericytes and endothelial cells, positive ALP enzyme reaction was detected in pericytes, which in vivo show only very weak enzyme reactivity. Treatment of cell cultures with ≤10 M retinoic acid had no effect in pure endothelial cell cultures, but did increase ALP expression of pericytes in co-cultures. The observation of a loss of endothelial ALP expression in vitro supports other in vitro as well as our own in vivo observations, indicating a negative correlation of ALP expression and proliferative activity of endothelial cells.
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    URL: http://dx.doi.org/10.1007/s004410051019
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    Polysome-like structures in the chromatoid body of rat spermatids (1998)
    Springer
    Cell & tissue research 291 (1998), S. 575-579 
    Details
    ISSN: 1432-0878
    Keywords: Key words Chromatoid body ; Polysomes ; RNA ; Spermatid ; Spermatogenesis ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  A procedure for isolating the chromatoid body from the testis of 40-day-old rats was developed. Electron-microscopical analysis indicated that about 70% of the isolated organelles were chromatoid bodies, while the remaining structures corresponded to dense bodies and probably to satellites. Negative staining of the isolated organelles revealed the presence of polysome-like structures in about 20% of the chromatoid bodies suggesting that the polysomes were not due to contamination with cytoplasmic polysomes. Moreover, the presence of RNA in the stroma of the chromatoid body was confirmed by RNAse-gold staining. Preliminary electrophoretic analysis of the RNA extracted from the organelles revealed the presence of a complex population of RNAs including 5.8 and 5 S ribosomal RNAs but no tRNA.
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    Edema formation in the rat larynx (1998)
    Springer
    Cell & tissue research 292 (1998), S. 367-375 
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    ISSN: 1432-0878
    Keywords: Key words Larynx ; Edema ; Mast cells ; Compound 48/80 ; Substance P ; Capsaicin ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  In the rat larynx, plasma exudation and edema formation were studied by light and electron microscopy after i.v. injections of the mast cell activator compound 48/80, substance P, and capsaicin. The morphological effects of substance P and capsaicin on connective tissue mast cells in vivo were also examined. Of the drugs tested, only compound 48/80 degranulated the connective tissue mast cells. All drugs induced a subepithelial plasma exudation in the subglottic region, with edema in the lamina propria and widened intraepithelial intercellular spaces, though the tight junction regions seemed intact. In the epiglottis, 10 min after compound 48/80 injection, there was edema in the lamina propria on the lingual side, with an intact and tight epithelial lining. No morphological sign of edema was found in the epiglottis after injection of substance P or capsaicin. The pronounced effect found in the epiglottic region after compound 48/80 injection was due to the release of mediators such as histamine and 5-hydroxytryptamine from the connective tissue mast cells. This study supports the belief that substance P in vivo mediates an increased vascular permeability by a direct effect on the blood vessels – a mechanism distinct from mast cell degranulation.
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    URL: http://dx.doi.org/10.1007/s004410051067
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    Internal division of capillaries in rat skeletal muscle in response to chronic vasodilator treatment with α1-antagonist prazosin (1998)
    Springer
    Cell & tissue research 293 (1998), S. 293-303 
    Details
    ISSN: 1432-0878
    Keywords: Key words Angiogenesis ; Capillary growth ; Prazosin ; Shear stress ; Skeletal muscle ; Ultrastructure ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Chronic vasodilatation represents a stimulus for capillary growth associated with increased luminal shear stress. We have examined the ultrastructure of more than 2000 capillaries to establish whether the sequence of angiogenesis in response to this stimulus is similar to that described during development and under pathological circumstances. Administration of the α1-blocker prazosin to rats for 2 weeks led to a greater capillary length density in extensor hallucis proprius muscles without any change in capillary tortuosity: J v(c,f)=262±54 compared with 350±17 mm–2, control compared with prazosin (P〈0.002). There were obvious signs of endothelial cell (EC) activation after prazosin treatment, including an increased proportion of capillaries with rough endoplasmic reticulum, large cytoplasmic vacuoles, thickened endothelium and an irregular luminal surface. Capillaries from control muscles had a maximum of three ECs in cross section, whereas four ECs were noted in 0.8+0.5% of capillaries after 1 week (n.s.) and 2.5±0.9% after 2 weeks (P〈0.01) of treatment. This could be due to elongation and/or migration of ECs, as cell proliferation has not been described at these time points. There was also an increase in the proportion of capillaries having a narrow, slit-like lumen (1.7±0.8% of controls; 7.1±1.9% at 1 week; 8.8±2.5% at 2 weeks; P〈0.02), some of which were smaller in size (less than 2 μm diameter) than in controls (3–5 μm) and/or “seamless”, i.e. lacking EC junctions. These may represent newly formed vessels. Focal discontinuity of the basement membrane and abluminal EC processes were rarely seen, and capillary growth by abluminal sprouting appeared to be very infrequent (less than 0.001% of profiles). Of more importance was growth starting from the luminal side. Significantly more thin cytoplasmic processes were observed protruding into the lumen of capillaries after 1 week (47.5±6.2%, P〈0.001) and 2 weeks of prazosin (34.2±5.5%, P〈0.05) than in control vessels (16.7±3.9%). Some of these traversed the entire lumen and connected with endothelium of the opposite side, probably involving membrane fusion, resulting in the appearance of a double lumen. Individual capillaries with a complete double lumen were observed after 2 weeks’ prazosin but comparatively rarely, in only four out of six muscles. These findings indicate a pattern of luminal growth which is completely different from intussusceptive growth previously described during development, and from the abluminal capillary sprouting seen under pathological circumstances.
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    Predation by juvenile roach on the calanoid copepod Eudiaptomus gracilis and the cyclopoid copepod Cyclops vicinus: a laboratory investigation with mixed and single prey (1998)
    Springer
    Aquatic ecology 32 (1998), S. 335-340 
    Details
    ISSN: 1573-5125
    Keywords: calanoid copepod ; cyclopoid copepod ; fish ; predation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We tested the outcome of predation by juvenile roach on the calanoid copepod Eudiaptomus gracilis and the similar sized cyclopoid copepod Cyclops vicinus in laboratory experiments with mixed and single-prey. When ovigerous females and adult non-ovigerous females of the calanoid copepod and the cyclopoid copepod were offered in equal numbers to the fish in the mixed-prey experiments, the cyclopoid copepods were significantly more heavily preyed upon than the calanoids. Between 14 and 16 females of the cyclopoid copepod and only between 2 and 4 calanoids had been consumed after the observation period of two hours. The single-prey experiments revealed that the conspicuousness of the calanoid vs the cyclopoid depended on sex and gravidity. Ovigerous females of the cyclopoid copepod were slightly earlier detected by the fish than ovigerous females of the calanoid, probably a result of the highly visible egg-sacs carried by the cyclopoid females. Females without eggs and males of the cyclopoid copepod were recognized later by the predator than females without eggs or males of the calanoid, probably a result of the different behaviours of the different copepod taxa. Cyclopoids frequently congregated near the aquarium bottom while calanoids were closer to the water surface where they were better visible. The calanoid copepod could better escape the fish's attacks than the cyclopoid copepod. Egg-bearing females of both the calanoid and the cyclopoid copepod could significantly better escape than non-ovigerous females or males. Probably ovigerous females react very early to water disturbances caused by the predator. Activity measurements showed that the cyclopoid copepod displayed 2 to 4 times more hops per time unit than the calanoid. Probably the high number of jerky movements displayed by the cyclopoid attracted attention of the predator and contributed to its greater vulnerability.
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    URL: http://dx.doi.org/10.1023/A:1009995432725
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    Negative Impact on the Aquatic Ecosystems of the State of Morelos, Mexico from Introduced Aquarium and Other Commercial Fish (1998)
    Springer
    Aquarium sciences and conservation 2 (1998), S. 67-78 
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    ISSN: 1573-1448
    Keywords: fish ; introductions ; management ; México ; native species
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Of the 22 fish species presently inhabiting the waters of the state of Morelos, México, more than half (64%) have been introduced, mainly for fisheries and ornamental aquaculture purposes. Even though there are other significant problems such as pollution, eutrophication and drought, we found that fish introductions have caused the worst ecological impacts. These problems stem from a general lack of knowledge regarding the characteristics, importance and appropriate use and management of aquatic resources. Conservational actions are proposed.
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    URL: http://dx.doi.org/10.1023/A:1009676403693
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    Changes in the abundance and diversity of coastal wetland fauna from the open water/macrophyte edge towards shore (1998)
    Springer
    Wetlands ecology and management 6 (1998), S. 59-68 
    Details
    ISSN: 1572-9834
    Keywords: marsh ; community structure ; physical and chemical ; fish ; zooplankton ; microcrustacea ; benthic ; Laurentian Great Lakes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Great Lakes coastal wetlands are widely recognized as areas of concentrated biodiversity and productivity, but the factors that influence diversity and productivity within these systems are largely unknown. Several recent studies have suggested that the abundance and diversity of flora and fauna in coastal wetlands may be related to distance from the open water/macrophyte edge. We examined this possibility for three faunal groups inhabiting a coastal wetland in Saginaw Bay, Lake Huron. We sampled crustacean zooplankton and benthic macro-invertebrates at five distances from open water in the summer 1994, and fish at three distances from open water in 1994 and 1995. We found significant spatial trends in the total abundance and diversity of zooplankton and fish, as well as the diversity of benthic macro-invertebrates. Zooplankton abundance and taxa richness were highest at intermediate distances from open water in a transition zone between the well-mixed bayward portion of the wetland, and the non-circulating nearshore area. Benthic macro-invertebrate taxa richness increased linearly with distance from open water. In contrast, fish abundance and species richness declined linearly and substantially (abundance by 78%, species richness by 40%) with distance from open water. Of the 40 taxa examined in this study, 21 had significant horizontal trends in abundance. This led to notable differences in community composition throughout the wetland. Our results suggest that distance from open water may be a primary determinant of the spatial distributions of numerous organismal groups inhabiting this coastal wetland. Several possible reasons for these distributions are discussed.
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    URL: http://dx.doi.org/10.1023/A:1008447705647
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    Swamp-riverine tropical fish population: a comparative study of two spatially isolated freshwater ecosystems in Peninsular Malaysia (1998)
    Springer
    Wetlands ecology and management 6 (1998), S. 261-268 
    Details
    ISSN: 1572-9834
    Keywords: Malaysia ; swamps ; freshwater ; fish ; riverine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Twenty-four fish species were collected during a study from October 1996 of the swamp-riverine fish populations of two spatially isolated Malaysian freshwater swamp ecosystems. Twenty one species were collected from the Beriah Kanan River, which is located in northern Peninsular Malaysia, compared to only 10 species obtained from the Ulu Sedili River in the south. At both sites, the species Rasbora einthovenii and Hemirhamphodon pogognathu appeared to be the most dominant species, whereas Rasbora pauciperforata and Nemacheilus selangoricus were very rarely caught and Beriah Kanan and Ulu Sedili River, respectively. An analysis of the physico-chemical data showed that although pH, conductivity and ammonium levels were fairly similar at both sites, orthophosphate, hardness and total suspended solids were relatively higher for Ulu Sedili River.
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    URL: http://dx.doi.org/10.1023/A:1008436005627
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    Flow-driven Diameter Response in Rat Femoral Arteries Perfused In Vitro (1998)
    Springer
    Annals of biomedical engineering 26 (1998), S. 526-533 
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    ISSN: 1573-9686
    Keywords: Rat ; Artery: femoral ; Arterial diameter ; Vasomotion ; Shear stress ; Flow-dependent constriction ; Step flow ; Oscillating flow
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Technology
    Notes: Abstract The effects of flow and flow changes on arterial diameter were investigated in vitro on isolated rat femoral arteries. Segments of femoral arteries were excised, mounted on microcannulas, and perfused with Tyrode's solution (37°C). Perfusion pressure was kept constant at 90 mm Hg. The mean external diameter after equilibration at a transmural pressure of 90 mm Hg was 720 ± 50 μ m (n=12). Vessels were then constricted with norepinephrine (1 μM in the superfusion solution) to 77% ± 13% of the resting diameter; acetylcholine was used to check endothelial function. The external diameter was measured continuously using video microscopy. The arteries were subjected to two different types of flow variations: (a) step changes in flow (increase and decrease, n=6) and (b) low-frequency sinusoidal flow variations (frequencies ranging from 0.002 to 0.1 Hz, n=11). Flow ranged from 0 to 800 μ l/min (shear stress ranging from 0 to 15 dyn/cm2). All measured vessels constricted as flow increased. Flow steps induced exponential-like contractions (flow increase) or relaxations (flow decrease) with mean characteristic time constants 31 ± 4 and 22 ± 2 s, respectively. Sinusoidal flow oscillations induced sinusoidal diameter oscillations with a time delay. An increase in the frequency of the flow led to a decrease of both the amplitude of the flow-induced diameter oscillations and the phase shift between flow and diameter. The dynamic diameter response to flow changes could be characterized by a first-order low-pass filter with a time constant of 22 s. © 1998 Biomedical Engineering Society. PAC98: 8745Hw
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    URL: http://dx.doi.org/10.1114/1.99
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    Evaluation of surgery procedures for tagging eel Anguilla anguilla with biotelemetry transmitters (1998)
    Springer
    Hydrobiologia 371-372 (1998), S. 107-111 
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    ISSN: 1573-5117
    Keywords: tagging ; surgery ; cyanoacrilate adhesive ; fish ; eel ; Anguilla anguilla
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Externally attached telemetry transmitters are unsuitable to tag yellow eels Anguilla anguilla (L.), in streams where they exhibit cryptic life habits and hide in narrow cavities between rocks. We evaluated the adequacy of surgical implantation and closing procedures for tagging eels with biotelemetry transmitters. Epoxy dummy transmitters (18 × 8 mm, 1.6–1.7 g) were implanted in eels anaesthetised with 2-phenoxy-ethanol (0.9 ml l-1), through a 20 mm mid ventral incision made in the posterior quarter of their body cavity. The incision was either left open, or closed in different ways: stitches (absorbable or non absorbable suture material) or commercial-grade cyanoacrilate adhesive (LoctiteTM). Fish were stocked in a 4 m2 flow through tank (15–17 °C), controlled daily for mortality and weekly for evaluating the healing process. No transmitter was expelled over a 12-week period, even in eels with unclosed incisions, of which 50% healed within 28 days (t 50). Regardless of the nature of the filament, suturing induced skin and muscle necrosis, caused significantly higher mortality rates (60% after 10 weeks) and paradoxically slowed down the healing rate (40 and 45 d, respectively). Cyanoacrilate suppressed the inflammatory response and granted higher survival rate (90%), but did not permit to speed up the closing process (t_50 = 52 d), as eels actively bit and removed the adhesive within hours. This behaviour was suppressed when we applied a freshly cut fragment of the eel dorsal fin as a biological bandage over the drying cyanoacrilate. The adhesive remained in place for one to two days and permitted to substantially increase the healing rate (t 50 = 15 d). These results substantiate the efficiency of surgery techniques for tagging eels with radio transmitters, at least for units of small weight and bulk.
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    URL: http://dx.doi.org/10.1023/A:1017090117425
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    Plasma concentrations of steroid hormones in male yellow perch, Perca flavescens: the effect of age and photothermal manipulation (1998)
    Springer
    Environmental biology of fishes 51 (1998), S. 97-105 
    Details
    ISSN: 1573-5133
    Keywords: fish ; 11-ketotestosterone ; testosterone ; estradiol ; sperm
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Plasma steroid concentrations in two and three year-old male yellow perch maintained under two different photothermal regimes were investigated. Initially, all fish kept indoors were exposed to the same water temperature (22 °C) and photoperiod (15L:9D). By the end of August, following the first sampling, fish were exposed to different photothermal regimes. Groups A2 (2 year old) and A3 (3 year old) were maintained under photothermal conditions similar to those of southern Ohio. Groups B2 (2 year old) and B3 (3 year old) were exposed to a condensed light/temperature regime designed to accelerate maturation. Testosterone (T) was the major circulating androgen in all groups. In regime A fish, plasma concentrations of 11-ketotestosterone (11KT) and T were very low in August, increased in October and remained elevated until March. In regime B plasma androgens were high until February and then dropped abruptly in March. The elevated circulating levels of 11KT and T were associated with production of sperm. The highest sperm concentration in the groups A3 and B3 was observed in February and December, respectively. There were no major differences in profiles and levels of plasma steroids between two age categories within each photothermal regime. These data indicate that the compression of the photothermal cycle accelerated both the occurrence of the low postspawning levels of circulating steroids and the completion of milt production. Higher sperm concentration observed in B3 group earlier in the season compared to A3 group also support the notion that the condensed photothermal cycle accelerated gonadal maturation. It appears that modification of the environmental cues may be a useful tool for manipulation of reproductive processes in male yellow perch.
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    URL: http://dx.doi.org/10.1023/A:1007460630535
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    Sex determination system of the rosy bitterling, Rhodeus ocellatus ocellatus (1998)
    Springer
    Environmental biology of fishes 52 (1998), S. 251-260 
    Details
    ISSN: 1573-5133
    Keywords: backcross ; crossover ; gynogenesis ; meiosis ; triploid ; fish
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The rosy bitterling, Rhodeus ocellatus ocellatus, is the only fish species known in which artificial triploids are always male, regardless of the kind of polyploidization technique used. In order to elucidate the genetic sex determination system of the rosy bitterling, two kinds of gynogenesis were carried out: retention of the second polar body (GRSPB) and suppression of the first cleavage (GSFC). The sex ratio of progeny was nearly 7:1 (♂:♀) for both GRSPB and GSFC, while those of control and parental fish were almost 1:1. In backcrosses of female progeny by GRSPB and normal diploid males, male progeny were observed at low frequency (one or two individuals in each experiment), except in one experiment where the appearance rate of males was about 50%. From results of gynogenesis and backcrosses, the following conclusions can be made. The genetic sex determination system of the rosy bitterling is a heterogametic female system (ZW). Survival rate of superfemales (WW), produced by gynogenesis, is much lower than that of males (ZW).There is a possibility that crossovers between sex determining genes and a centromere occur in the first meiosis. With repect to the mechanism of unisexuality (male) of artificial triploids of the rosy bitterling, only males (ZZZ and ZZW) are presumed viable, while females (ZWW) are probably inviable.
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    Osteology of Zacco pachycephalus, sensu Jordan & Evermann (1903), with special reference to its systematic position (1998)
    Springer
    Environmental biology of fishes 52 (1998), S. 163-171 
    Details
    ISSN: 1573-5133
    Keywords: Formosan cyprinid ; skeletal system ; Opsariichthys ; fish
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The skeletal system of Zacco pachycephalus, sensu Jordan & Evermann (1903), is described and compared with that of other related barilines to clarify its systematic position. Osteological characters fall generally into two categories in terms of apomorphic features. The first category is exemplified by autapomorphies such as lower jaw bone shape and the number of branchiostegal rays and hypurals. The latter characters are highly unusual among Cyprinidae. The second category consists of synapomorphies linking Z. pachycephalus and Opsariichthys uncirostris. Specialization of jaw bones for a piscivorous habit is also notable. The quadrate-pterygoid fenestra of Z. pachycephalus and O. uncirostris is considered derived. We conclude that Zacco pachycephalus should be transferred from Zacco to Opsariichthys based on the present osteological analysis.
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    Variations in age and size at maturity of female Nile tilapia, Oreochromis niloticus, populations from man-made lakes of Côte d'Ivoire (1998)
    Springer
    Environmental biology of fishes 52 (1998), S. 453-465 
    Details
    ISSN: 1573-5133
    Keywords: phenotypic plasticity ; reproductive style ; fish ; cichlid
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The reproductive characteristics of Oreochromis niloticus females were studied in two large hydroelectric dams and 6 small agropastoral reservoirs of Côte d'Ivoire, selected for their diversity of environmental conditions and sizes (6 to 80000 ha). Comparative analysis of age and size at maturity revealed large differences between the populations with early maturity, late maturity, and intermediate situations. All the populations matured in their first year, between 5.6 and 10 months. Age and size at maturity were positively correlated with the reservoir area. The range of variation in age at maturity between populations was far greater than that of size at maturity. However, size at maturity also appears to be very plastic as intra-population variations of 2 to 3 cm were found between consecutive years. A comparison of age at maturity for a population in 1994 and 1996 showed that this trait is also likely to vary significantly at the intra-population level. Environmental factors which could potentially affect age and size at maturity are discussed. Growth differences are the probable explanation for the observed patterns of variation between populations. Rapid changes in age and size at maturity at inter or intra-population levels suggest that the observed variations might be explained by differences in environmental variables (phenotypic plasticity) rather than by genetic differences.
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    Electronic Resource
    Electronic Resource
    Comparative ecology and historical biogeography of the genus Brachyrhaphis (1998)
    Springer
    Environmental biology of fishes 51 (1998), S. 117-127 
    Details
    ISSN: 1573-5133
    Keywords: poeciliid ; area cladogram ; fish
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Phylogenetic systematics was used to reveal micro-evolutionary processes and macro-evolutionary patterns that have resulted in the current distribution of species of the live-bearing fish genus Brachyrhaphis. A previously constructed molecular phylogeny for the genus determined that two distinct clades, deep-bodied and slender-bodied, exist within the genus. Micro-habitat variables were measured for all extant members of the genus. Water flow differed significantly between the clades and was converted to a discrete variable and, along with elevation and micro-habitat type, mapped onto the phylogeny for the genus. The evolution of micro-habitat choice was hypothesized using these results. A detailed distribution map was constructed to unveil biogeographic patterns and was also interpreted in light of the molecular phylogeny. The phylogeny was then used to construct an area cladogram. This cladogram was compared to the one derived from paleogeography. The molecular-based area cladogram adds to the growing database required to resolve the biogeography of the Caribbean.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1007415928796
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