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  • 1977  (43,877)
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  • 1990-1994
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  • 1975-1979  (43,877)
  • 1940-1944
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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Zoomorphology 86 (1977), S. 197-222 
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The ultrastructure of monociliary receptors in 10 species of the Proseriata and Neorhabdocoela is described, with particular reference to the epidermal dendritic part. Sensory cells with a single kinocilium situated at the level of the distal epidermis membrane are considered as mechano- or chemoreceptors. There exist sensory cells with a dendrite penetrating one epidermis cell and bearing an embedded kinocilium and a collar of 8 stereocilia or ridges with a fribrillose substructure. These collared receptors probably function as mechanoreceptors. In comparison with collared sensory cells in species of other turbellarian orders, the embedded receptors in the Proseriata and Neorhabdocoela are more advanced and possess synapomorphous characteristics. With the embedded receptors a new evidence is given for the close phylogenetic relationship between the Proseriata and Neorhabdocoela. The distribution of collared cells in the animal system and their phylogenetic implication for a choanoflagellate origin of the Metazoa are briefly discussed.
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  • 2
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    Zoomorphology 86 (1977), S. 251-270 
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Die Rektalpapillen vonThrips bestehen aus vier Typen von Zellen, die eine polsterförmige Aufwölbung mit einem abgeschlossenen Hohlraum bilden. Die innere Zellschicht besteht aus fünf großen Hauptzellen und einer Kanalzelle. Die Hauptzellen enthalten Glykogen in Form vonβ-Granula und multivesikuläre Körper. Ihre apikale Zellmembran bildet einen Faltensaum mit einem regelmäßigen Partikelbesatz auf der Innenseite und angelagerten Mitochondrien. Die laterale Plasmamembran der Hauptzellen hat einen gewundenen Verlauf und steht in engem Kontakt zu zahlreichen Mitochondrien. Die Flüssigkeit in den Interzellularräumen des Hauptzellkomplexes wird über einen Kanal zum zentralen Hohlraum der Papille abgeleitet; er wird von einem gebogenen rüsselförmigen Fortsatz der Kanalzellen gebildet. Die äußere Schicht der Papille besteht aus einer inneren und einer äußeren Nebenzelle. Ihre Differenzierungen zum Flüssigkeitstransport sind deutlich, aber allgemein weniger hoch entwickelt. Eine offene Verbindung vom Lumen der Papille zum Haemocoel wurde nicht gefunden. Verbindungszellen bilden den Übergang von der Papille zum übrigen Rektalepithel. Axonendigungen mit Neurosekret liegen an der Papillenbasis. Die möglichen Wege des Flüssigkeitstransports werden diskutiert, und der Aufbau derThrips-Papillen wird mit dem bei anderen Insekten verglichen.
    Notes: Summary The rectal papillae ofThrips consist of four types of cells arranged as a closed hollow pad. The inner layer is composed of five large primary cells (“Hauptzellen”) and of a drain cell (“Kanalzelle”). The primary cells contain glycogen in form ofβ-granula, and multivesicular bodies. Their apical cell membrane, forming numerous leaflets is associated with mitochondria and with a coat of repeating subunits on the cytoplasmic surface. The lateral plasma membrane of the primary cells has a sinuous course and is in close contact with numerous mitochondria. The intercellular spaces of the primary cell complex are drained to the central cavity of the papilla by a discharge formed by a curved elephant's trunk-like process of the drain cell. The outer layer of the papilla consists of an inner and an outer secondary cell (“Nebenzellen”). Their differentiations related to fluid transport are evident, but generally less elaborate. An open communication of the lumen of the papilla with the haemocoel was not detected. The papilla is connected with the rest of the rectal epithelium by junctional cells (“Verbindungszellen”). Neurosecretory terminals are present at the base of the papillae. The possible ways of fluid transport are discussed and the structure of theThrips papilla is compared with that in other insects.
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  • 3
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The scincid lizardTiliqua rugosa possesses a large external nasal gland which is located intraconchally. Highly ramified tubules, imbedded primarily in the periphery of the gland, unite to form collecting ducts which empty into a short excretory canal. The diameter of the tubules increases progressively from 30Μ. at the distal extremity of the gland to over 200Μ at the level of the collecting ducts. The intraglandular portion of the excretory canal is often dilated to form an ampulla. The thickness of the epithelium increases from 12Μ at the level of the tubules to 25–30Μ in the excretory canal. The excretory canal is lined with an epidermal epithelium close to the point where it enters the vestibule. In all the rest of the gland the tubules are lined with two cell types: large, typical muco-serous cells and “striated” cells. At the distal end of the tubules the “striated” cells are narrow and poorly differentiated and alternate more-or-less regularly with the muco-serous cells. The relative proportion of these “striated” cells increases progressively, as does their size, as one moves proximally down the tubule. In the gland as a whole the “striated” cells are approximately twice as numerous as the muco-serous cells but, due to their smaller size, they occupy less than one third of the tubular volume. Electron microscopy of the “striated” cells ofTiliqua rugosa revealed the presence of extensive lateral interdigitations and expansions of the basal cytoplasmic membrane, anatomical specialisations which are normally indicative of active salt transport. These modifications are less marked however than in the external nasal glands of the lizardsLacerta muralis andVaranus griseus, which do not appear to function as salt glands. In addition there are few mitochondria present, although they are of large size. The combination of these ultrastructural features, plus the fact that the “striated” cells are intermixed with muco-serous cells in the tubules, makes it most unlikely that the external nasal gland ofTiliqua rugosa is capable of elaborating an hyperosmotic fluid. What is more, this has never been conclusively demonstrated in this species in physiological studies. The progressive specialisation of the “striated” cells from the distal to the proximal section of the tubules poses the problem of the origin and differentiation of this cell type. A review of results obtained from the study ofTiliqua rugosa and other species of lizards shows that the nature of the relationship between structure and function of the external nasal gland is far from clear. The existence of “salt glands”, capable of excreting hyperosmotic solutions, is invariably linked with the presence in the gland of well-developed “striated segments” composed almost entirely of cells possessing extensive interdigitations of the lateral membranes. Amongst terrestrial lizards, nasal salt glands are usually found in herbivorous species and they are primarily adapted to the extrarenal excretion of potassium ions. The problem for carnivorous species is more often that of an excess of sodium rather than potassium ions and with the possible exceptionAcanthodactylus species, functional nasal salt glands have not been demonstrated in terrestrial carnivores, despite the presence in some cases of well-developed “striated segments” in the gland having a similar structure to those found in herbivores. In humid regions, carnivorous lizards probably never require extrarenal excretory mechanism and in arid regions their survival is assured by their capacity to tolerate hypernatraemia when confronted with excessive salt loads. Salt glands capable of eliminating sodium ions to any extent have only been described in two littoral species, an herbivorous iguanid and a carnivorous varanid. Unfortunately the structure of their respective nasal glands has not yet been described and their further study would be desirable.
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  • 4
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    Zoomorphology 87 (1977), S. 147-153 
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Resume Trois types de parois ont été décrits dans l'appareil circulatoire du tronc dePhoronis psammophila. La succession des diverses couches de chaque type est la suivante: 1. cellules “péritonéales” — lame basale — rares cellules endothéliales; 2. cellules myoépithéliales — lame basale — rares cellules endothéliales; 3. une couche de muscles circukires, puis une de muscles longitudinaux — épaisse lame basale — endothélium continu.
    Notes: Summary Three types of wall structure of blood vessels have been described. It consists of the following distinct layers, from exterior to interior: 1. “peritoneal” cells — thin basal lamina — some endothelial cells; 2. myoepithelial cells resting on a basal lamina — some endothelial cells; 3. circular and longitudinal muscle layers of myoepithelial cells — thick basal lamina — continuous endothelial lining.
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  • 5
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    Zoomorphology 87 (1977), S. 191-202 
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung 1. Es werden das Lateralorgansystem, das Labyrinth, der Geschmacksapparat und die Nase des BrotulidenTyphliasina pearsei (Hubbs, 1938) morphologisch untersucht und in Beziehung zur Lebensweise dieser Höhlenfische gebracht. 2. Das Lateralsystem ist hochentwickelt und auf den Kopf konzentriert. Besonders das Kanalsystem hat morphologische Abwandlungen erfahren. Durch Kopplung eines DruckempfÄngers (Membrankapseln des Kanalsystems) und eines GeschwindigkeitsempfÄngers (Neuromastencupula) hat sich ein ReizverstÄrker entwickelt, der imstande ist, feinste Staudruckerscheinungen für die Raumorientierung nutzbar zu machen und spezifische Verhaltenssignale zu vermitteln. Die mit Strömungsrezeptoren versehenen Kanalporen der Schnauzenspitze steuern überwiegend die Nahrungssuche. 3. Demgegenüber sind chemorezeptorische Sinnesorgane gering entwickelt. Der Rumpf und auch die fadenförmigen Ventralen besitzen keine Geschmacksknospen. Dennoch ist ein Ramus lateralis accessorius ausgebildet, der in Verlaufsmuster und Lagebeziehung zu den Flossen dem der Gadiden Ähnlich ist. 4. Das olfaktorische Epithel (3 Lamellen) und der Olfactorius sind schwach entwickelt. Die Bulbi olfactorii sind dem Vorderhirn angelagert. 5. Das Labyrinth zeichnet sich durch einen auffallend gro\en Otolithen des Sacculus aus, der mit der Spezialisierung auf niederfrequente Töne in Zusammenhang gebracht wird.
    Notes: Summary 1. These studies are concerned with the morphology of the lateral-line organ, the labyrinth, the gustatory apparatus and the nasal organs of the brotulid fishTyphliasina pearsei (Hubbs, 1938) and its relations to the mode of living of the cavernicolous fish. 2. The lateral-line system is highly developed and concentrated to the head. Especially the canal system of the head has passed through morphological alterations, which enable the fish to perceive very slight water displacements. By the way of connecting a pressure receiver (membran-covered boxes of the canal system) and a velocity receiver (cupula of the neuromast) there is made up a stimulus amplifier, being able to utilize very weak damming phenomena for orientation of space and to mediate specific signals of behaviour. The canal pores on the tip of the snout which are supported with current receptors preponderantly control the search of food. 3. In contrast to mechanoreceptors the sense organs of chemoreception are poorly developed. There are no taste buds on the body and neither on the filamentous pelvic fins. Nevertheless, we find a ramus lateralis accessorius, which resembles that of Gadidae with regard to the pattern of course and the morphological relationships to the fins. 4. The olfactory epithelium (3 lamellar folds) and the olfactorius are small in size. The bulbi olfactorii are directly situated in front of the telencephalon. 5. The labyrinth is characterized by a remarkably enlarged saccular otolith, which is supposed to be specialized in receiving sounds of low frequency.
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  • 6
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    Zoomorphology 87 (1977), S. 263-276 
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Alle Teile des männlichen Genitaltraktes vonOpisthopatus cinctipes sind an der Entstehung der Spermatophore beteiligt. In den Spermatocyten der Hoden werden in großer Zahl elektronendichte Sekreteinschlüsse produziert, die in den Vesiculae seminales zusammenfließen und aus der Spermatide in das Vesicula-Lumen entlassen werden. Während der Spermiocytogenese wird ein zweiter Typ von Einschlußkörpern gebildet, den wir als Akrosom-Vesikel deuten; auch er wird in der Samenblase ausgeschleust. In der Passage durch die Vasa efferentia werden fast reife Spermien und Sekret voneinander getrennt. An der Peripherie liegen die Sekrete, im Zentrum die Spermien. Im Vas deferens werden die Samenpakete von einer mehrschichtigen Sekrethülle umgeben. Durch den muskulösen Ductus ejaculatorius wird die Spermatophore abgegeben, auch in ihm finden sich Drüsenzellen. Dem Transport dienen in Vasa efferentia und Vas deferens Cilien.
    Notes: Summary All parts of the male genital tract ofOpisthopatus cinctipes are involved with the formation of the Spermatophore. In the spermatocytes within the testes a Golgi apparatus produces electron dense secretory granules merging into one large droplet, which is extruded by the spermatid within the seminal vesicle. A second vesicular structure is formed near the plasmamembrane of the spermatids by a Golgi apparatus. It is presumably an acrosome vesicle and is extruded into the seminal vesicle, too. During the passage through the vasa efferentia secretory products and sperm-cells are separated from each other, the secretory products building an envelope around the spermatozoa. The epithelium of the vas deferens adds a multilayered outer covering. Some parts of the male genital tract bear cilia (vasa efferentia, vas deferens).
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  • 7
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary To determine the degree of systematic affinity between branchiobdellids and lumbriculids, the ultrastructures of muscle and sperm cells ofBranchiobdella pentodonta andBythonomus lemani were studied. The structure ofBranchiobdella sperms is similar to that of the oligochaete model in terms of nucleus and the middle piece and to that of the hirudinean model in the peculiarity of the flagellum and acrosomal complex. Muscle ofBranchiobdella are very similar to those of the hirudineans. Muscles and sperms ofBythonomus lemani are practically identical to those of the tubificid model and are closely related to the other known oligochaetes.
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  • 8
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    Zoomorphology 88 (1977), S. 81-94 
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Twenty-one species of Porifera have been surveyed by light microscopy for the presence, form, and relative abundance of a little known cell type known as central cells. They are found to be present in fifteen of these species and occur in six morphologically recognizable forms. Their functional roles are reinterpreted in the light of new distributional and abundance data. The central cells of the siliceous ceractinomorph demosponges are common and intimately associated with the choanocyte population. They probably play an important role in control of water currents within individual choanocyte chambers to mediate cleaning of the outer chamber surfaces. The central cells of keratosan and tetractinomorph demosponges appear to represent stages in egestive processes of wandering mesenchyme cells.
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  • 9
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Die Ultrastruktur pericerebral gelegener Cilienaggregate vonDicoelandropora atriopapillata Ax, 1956, undNotocaryoplanella glandulosa (Ax, 1951) wird beschrieben. Die intracellulÄren Aggregate setzen sich jeweils aus mehreren 100 Cilien zusammen, die lückenlos alternierend angeordnet und distal miteinander verflochten sind. Für die Cilienaggregate wird eine photoreceptorische Funktion wahrscheinlich gemacht.
    Notes: Summary The ultrastructure of pericerebrally located ciliary aggregations inDicoelandropora atriopapillata Ax, 1956, andNotocaryoplanella glandulosa (Ax, 1951) is described. The intracellular aggregations consist of some 100 cilia, which are arranged in an alternating position without gaps. The distal parts of the cilia are interweaved. The aggregations are interpreted as photoreceptors.
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  • 10
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary European populations of the turbellarianMesostoma ehrenbergii can produce two types of eggs according to a seasonal cycle. Subitaneous eggs (S eggs) are produced throughout the warm season and develop rapidly inside the parental uteri. They are meant to ensure a fast increase in the number of worms. Dormant eggs (D eggs) are produced during the warm season and are usually deposited in water at the death of the parent. They can hatch at the beginning of the next warm season and are, therefore, meant to ensure the survival of the population throughout the cold season, when adult worms are no longer present. S eggs are bounded by a thin, translucent covering which has a loose structure and is mainly proteinaceous in composition. These characteristics account for the functional role played by the S egg covering during embryonic development. The covering has, in fact, to be permeable to parental nutrients, and to keep pace, by stretching, with the enlargement of the embryo. By contrast, D eggs are bounded by a thick shell, presumably composed of a sclerotin, the precursors of which (polyphenols) are synthesized together with yolk in the vitelline cells. The shell has a smooth surface devoid of pores and has the function of isolating the developing D egg from the external environment.
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  • 11
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    Wood science and technology 11 (1977), S. 1-1 
    ISSN: 1432-5225
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
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  • 12
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    Wood science and technology 11 (1977), S. 33-38 
    ISSN: 1432-5225
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary Fast or abnormal (tumor) growth does not substantially affect wood substance and cell wall density. Consequently, void volume of dry cell walls is also not substantially affected.
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  • 13
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    Wood science and technology 11 (1977), S. 3-22 
    ISSN: 1432-5225
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary This is a study on the shrinkage of wood representing the wide range of morphology variation in leaning trees. It involved 13 trees of Eucalyptus regnans, one of Eucalyptus sieberi and four of Pinus radiata, and specimens taken at close intervals around the circumference of each. Data indicated a systematic modulation, between extremes at upper and lower sides of each stem, in longitudinal growth strains, relative proportions of thin, medium and thick-walled fibres, microfibril angle in the S2 layer of these, and both Klason and acid-soluble lignin content. Analyses indicated that the microfibril angle in S2 was a prime factor in influencing both longitudinal and volumetric shrinkage reactions; proportion of thick-walled fibres in the tissue, thickness of S2 relative to S1, and variations in lignification also were involved. Unusually thick-walled fibres were associated with visco-elastic strain recovery effects, which could form a substantial part of dimensional changes apparently attributable to shrinkage.
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  • 14
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    Wood science and technology 11 (1977), S. 39-49 
    ISSN: 1432-5225
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Calculations of the monomolecular water vapor adsorption by three different celluloses (cotton, wood pulp and cellophane) from structural considerations are in agreement with the BET determined values for crystallite diameters of 16 to 200 Å on the basis of adsorption being confined to the fraction f of the three hydroxyl groups per anhydroglucose unit that are available on the surface of the crystallites and within the amorphous zones, when f ranges from 0.16 to 0.29. These low values of f are compatible with the fact that the void volume of the amorphous zones does not exceed about 6%. More exact values for f are needed before more definite values for the crystallite diameters can be estimated. A modified fringe micelle diagram containing a considerable amount of chain association in the amorphous zones is given that meets the requirement dictated by the calculations. Another approach, involving direct estimation of the adsorbing surface areas of crystallites and amorphous zones, on the basis of adjacent surfaces being shared by water molecules adsorbed between them, gives surface areas somewhat larger than the BET values using the same f values. Agreement with values from the former approach is obtained if only 75% of the surface per anhydroglucose unit is considered effective for adsorption.
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  • 15
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    Wood science and technology 11 (1977), S. 59-67 
    ISSN: 1432-5225
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Mycelium of twenty species of wood-destroying fungi was cultivated in nutrient solutions with one of the following sugars as the only carbon source: glucose, arabinose, galactose, mannose and xylose. The growth of the species occurring in nature only on the wood of Angiosperms was equal or lower in the solutions with galactose and mannose than in the solution with glucose. The utilization of mannose was practically the same as that of xylose. The species which are specialized in nature in the wood of conifers grow better in the solutions with galactose and mannose, than in the solution with glucose; likewise mannose is beter utilized than xylose. Fungi attacking both kinds of wood do not exhibit any dependence on the utilization of the sugars used in these investigations.
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  • 16
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    Wood science and technology 11 (1977), S. 79-81 
    ISSN: 1432-5225
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
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  • 17
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    Wood science and technology 11 (1977), S. 115-123 
    ISSN: 1432-5225
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Tangential pit features were studied in a 55-year old black spruce (Picea mariana (Mill) B.S.P.) tree by means of light and electron microscopy. It was found that tangential pitting is lacking from the greatest part of the growth ring, except for the last four tangential rows of latewood tracheids and the first row of early wood tracheids. The average number of pits per tangential wall of a 3.55-mm-long tracheid is 234, 144, 28, 4 and zero, respectively, in the last 5 tangential rows of latewood tracheids, starting at the growth-ring boundary. On the average, tangential pits measure 5.4 μm in diameter, possess oval to elliptical apertures, and are randomly distributed uniformly over the tangential tracheid wall. All tangential intertracheid pits are bordered and in that respect are similar to those in the radial walls. Although most of the pits contain membranes with tori, some at the growth-ring boundary lack tori and exhibit randomly oriented microfibrillar structure.
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  • 18
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    Wood science and technology 11 (1977), S. 125-131 
    ISSN: 1432-5225
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary Preliminary investigations were carried out aiming at the establishment of relationships between chemical, physical, and mechanical properties of beech wood under the influence of heating in water at 50°C and 100°C at pH values from 2.8 to 8.5 and with heating times up to 25 hours. It was found that heating of beech wood in water at 50°C does not produce remarkable changes in its properties. When green wood was heated at 100°C, insignificant changes in its density, shrinking, and α-cellulose content were observed, whereas a considerable decrease in strength was found when tested in a wet state. It was further observed that on prolonged heating, the reactions of the wood and the solutions used as a heating medium under-went distinct changes, attaining an equivalent value approximating the final pH of the wood.
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  • 19
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    Wood science and technology 11 (1977), S. 147-151 
    ISSN: 1432-5225
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary In previous papers, a theory was developed relating Young's modulus of hydrogenbond dominated solids to the density of this bond and to its parameters, and also to the moisture content of the solid. In this paper, the theory is applied to experimental results reported by Cousins on periodate lignin. The theory fits the observations and, furthermore, predicts that this particular lignin has 6.84 potential H-bonding sites per repeating unit of an assumed molecular weight of 1,000. No data for periodate lignin exist, but a Freudenberg constitutional scheme for lignin postulates a little over 7 potential sites for H-bonding per repeating unit of 1,000 molecular weight.
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  • 20
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    Wood science and technology 11 (1977), S. 153-167 
    ISSN: 1432-5225
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary Metabolic differences in the formation of guaiacyl and syringyl lignins were explained in terms of the different functions of O-methyltransferases and reducing enzymes which participate in methylation and reduction of the hydroxycinnamic acid intermediates in the biosynthetic pathway of these two types of lignins. Sinapyl alcohol was dehydrogenated with peroxidase and H2O2 under various reaction conditions. Chemical properties of the dehydrogenation polymers (DHPs) formed were characterized, and the possible occurrence of syringyl lignin in hardwood was discussed. DHP and dimers of p-coumaryl alcohol were also characterized and discussed in relation to the formation of grass lignin which contains p-hydroxyphenyl propane as an additional lignin monomer.
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  • 21
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    Wood science and technology 11 (1977), S. 249-250 
    ISSN: 1432-5225
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
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  • 22
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    Wood science and technology 11 (1977), S. 225-236 
    ISSN: 1432-5225
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary A technique was developed for the determination of the effective dissolved oxygen diffusivity in liquid-saturated softwood in a diffusion cell under ambient pressure. From the measurements in the temperature range 2° to 50°C, the activation energy of diffusion was found to be 4.6 kcal/mole. The diffusivity in summerwood is about one half of that in springwood. The diffusivity of dissolved oxygen through composite springwood and summerwood layers was based upon samples of two Douglas fir sapwood blocks saturated with water. In the radial and tangential directions, diffusivity was 1.4 to 2.3x10-6cm2/s, which is about 6 to 10% that of dissolved oxygen diffusivity in water. The diffusivity in the longitudinal direction is about 5.5 times that in the other two directions. The diffusivity of dissolved oxygen through liquor-saturated wood and the effect of delignification on oxygen diffusion were also determined.
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    Wood science and technology 11 (1977), S. 251-263 
    ISSN: 1432-5225
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    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary The structure of the reducing end group in xylan can be written: -β-D-Xylp-(1→4)-β-D-Xylp-(1→3)-α-L-Rhap-(1→2)--α-D-GalpA-(1→4)-D-Xyl In alkaline media the reducing xylose group is easily isomerized and removed by a β-elimination which leads to a reducing galacturonic acid end group. The 1, 2-linkage between rhamnose and the galacturonic acid explains the retarding effect on the alkaline peeling. Even under fairly mild conditions the galacturonic acid group is converted to other groups which are very stable in alkaline media. Model experiments permit the conclusion that OH-3 in the reducing group is subjected to β-hydroxyelimination. The 3-deoxy-2-O-α-L-rhamnopyranosyl-D-threo-hex-2-enuronic acid group formed is unstable in acid medium and escapes observation by the techniques employed for determination of the end groups. Upon prolonged alkaline treatment and increased proportion of these groups is lost and a rapid peeling proceeds until a xylose group with a 4-O-methylglucuronic acid substituent is liberated. The consecutive reactions of this group are similar to those of the galacturonic acid groups. The formation of 3-deoxyaldonic acid end groups, an important stopping reaction in cellulose, is of minor importance in xylan.
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    Wood science and technology 11 (1977), S. 322-322 
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    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
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    Zoomorphology 86 (1977), S. 155-167 
    ISSN: 1432-234X
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    Topics: Biology
    Description / Table of Contents: Zusammenfassung Tergale Längsrippen auf dem Peräon finden sich in folgenden Isopoden-Familien: Trichoniscidae, Buddelundiellidae, Stenoniscidae, Tendosphaeridae, Oniscidae, Platyarthridae, Pentheidae (= Armadillidae). Es wird angenommen, daß sich diese Rippen durch ähnliche ökologische Bedingungen konvergent in den genannten Familien entwickelt haben. Alle behandelten Gruppen zeigen ein ähnliches Rippenmuster. Pro Tergit können 6–12 Rippen vorkommen. Drei Rippentypen können unterschieden werden: 1. derCretoniscellus aegaeus-Typ mit abgerundeten Längserhebungen ohne zusätzliche Strukturen; 2. derHaplo-phthalmus-montivagus-Typ mit einer Reihe von spitzen Höckern entlang dem Rippengrat; 3. derPlatyarthrus-schoebli-Typ mit einer Reihe von der Rippe aufgesetzten großen Schuppenborsten. Ontogenetische Beobachtungen anHaplophthalmus zeigen, daß frischgeschlüpfte Jungtiere die gleiche absolute Rippenhöhe und dieselbe Anzahl der Rippen pro Tergit besitzen wie adulte Tiere. Es wird angenommen, daß die Funktion der Rippen darin besteht, bei Kontakt der tergalen Überfläche mit feuchtem Substrat die dabei auftretenden Adhäsionskräfte zu verringern. Die Rippen müssen demnach (im Zusammenhang mit anderen strukturellen Differenzierungen) als eine wichtige morphologische Anpassung an ein bestimmtes Habitat betrachtet werden. Dieses Habitat ist in der Regel der untere Teil der Humusschicht, der durch enge Zwischenräume und durch permanent gesättigte Luftfeuchtigkeit ausgezeichnet ist. In einem Anhang werden die tergalen Strukturen innerhalb der GattungPlatyarthrus und ihre ökologischen Zusammenhänge analysiert.
    Notes: Summary Longitudinal tergal peraeon-ridges are found in the following isopod families: Trichoniscidae, Buddelundiellidae, Stenoniscidae, Tendosphaeridae, Oniscidae, Platyarthridae, Pentheidae (= Armadillidae). It is presumed that these ridges evolved convergently in the families cited above under similar ecological conditions. The ridge-pattern is similar in all treated groups. There are 6–12 ridges on each peraeon-tergite. Three types of ridges can be differenciated: 1) theCretoniscellus-aegaeus-type showing rounded ridges without accessory structures; 2) theHaplophthalmusmontivagus- type with a row of pointed spikes on top of the ridge; 3) thePlatyarthrus-schoebli- type with a row of big scale-spines situated on the ridge. Ontogenetic observations inHaplophthalmus show that the absolute hight of the ridge and the number of ridges per tergite are the same in newly hatched juveniles as in adults. The function of the ridges is supposed to be a means to reduce the adhesive forces in case the tergal surface comes into contact with wet substrate. The ridges are to be considered an important adaptation (seen in connection with other structural differenciations) for a special habitat which is the under-storey of the litter stratum. This habitat is characterized by very small interstices, and by a permanently saturated moisture. An appendix is dedicated to a tentative analysis of the tergal structures in the genusPlatyarthrus seen in an ecological context.
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    Wood science and technology 11 (1977), S. 219-223 
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    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary A large number of reducing xylose end groups are present in birch wood (Betula verrucosa) while all galacturonic acid moieties are non-reducing. A large portion of the reducing xylose end groups are removed during treatments with alkali used for the islation of xylan, while reducing galacturonic acid moieties are formed by endwise degradation during this procedure.
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  • 27
    ISSN: 1432-5225
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    Notes: Summary Naturally-occurring growth stress patterns in timber are modified by cutting. Stresses in cut timber may cause destructive cracks and splits. This research uses a three-dimensional finite element method to study how non-axisymmetric cuts affect the stress pattern. The results show that some oblique cuts reduce high stresses near the pith. Experimental work supports the calculations.
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    Wood science and technology 11 (1977), S. 265-274 
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    Notes: Summary Cryo-ultramicrotomy was applied to holocellulose and alpha-cellulose from spruce wood (Picea abies Karst.) for a light and electron microscopical study of the removal of lignin during chlorite delignification and the changes in swelling during delignification and alkali extraction. The swelling state of the fibre walls during each stage of treatment was well preserved, and distinct differences could be observed. Staining with uranyl acetate brought out the fine structure of the fibre walls down to the range of elementary fibrils.
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    Wood science and technology 11 (1977), S. 275-290 
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    Notes: Abstract Investigations on enzymic hydrolysis of cotton cellulose and spruce groundwood pulp with the multicomponent enzyme Onozuka SS have shown that lignin causes an almost total inhibition of the enzyme action. Breaking of lignified covers of cell walls and fibrillar bundles by grinding increases the accessibility toward the enzyme very effectively. Depolymerization of lignin is less important for improving the accessibility. The compact fibrillar structure of both cotton and wood cellulose also have an inhibitory effect on the penetration of the enzyme into the fiber. Beating loosens the compactness of the fibrillar structure and increases the accessibility. Only about 10% of the cellulose, probably highly crystalline, requires more drastic treatment e.g. ball-milling. Last units of polysaccharides linked to lignin in the lignin carbohydrate complex are resistant toward enzyme hydrolysis and require chemical cleavage. Total enzymic solubilization of lignified polysaccharides can therefore be attained only after a combined mechanical and chemical pretreatment.
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    Wood science and technology 11 (1977), S. 305-312 
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    Notes: Summary Using the assumptions made on growth-stress related parameters in Part I, several optimization problems are posed. Finite element and optimization techniques show that for axisymmetric geometries, while cracking may be reduced by making cuts of special shapes, a compensating amount of wood is destroyed by making the cut. Also included in this study are banding of the log and stepped cuts with application of radial pressure. The results show that some combinations of radial pressure and the extent over which it is applied remove the most highly stressed wood.
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    Wood science and technology 11 (1977), S. 319-321 
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    Wood science and technology 11 (1977), S. 291-303 
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    Notes: Abstract The physical properties and morphology of kraft paper handsheets obtained from tension wood of intensively managed, 5-year-old trees of Populus “Tristis No. 1” were compared to those produced from isolated normal wood of the same stems. Pulp yields of tension wood (TW) and normal wood (NW) were 60 and 53% respectively. Over a beating range of 0–45 minutes, strength properties of TW paper were in all cases noticeably inferior to those obtained from NW. During paper formation, the TW or gelatinous fibers resisted collapse, even upon extended refining, and produced thick, porous sheets of poorly bonded elements. It was concluded that the differential behavior of NW and TW pulps was in several respects analogous to those displayed by earlywood and latewood pulps, respectively, of softwood species as well as thin-vs. thick-walled hardwood fibers. Consequently, it appears that the inferior strength of TW paper is primarily a function of fiber morphology, and the difference in hemicellulose content between NW and TW (viz., lower pentosan content of TW) often cited in the literature as a potential major factor here probably contributes little if any significant effect on ultimate interfiber bonding and paper quality.
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    Wood science and technology 11 (1977), S. 313-318 
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    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary Warts have been observed in several bamboo species; they are present not only in vessel members and fibres, but also in the highly lignified parenchyma cells, especially in those of the elongated type. Among the 34 species studies only a few possess warts in all three cell types. The sizes of warts lie within the range observed for dicots and gymnosperms. There is no recognizable correlation between the occurrence of warts and the taxonomic grouping of bamboos. It has been suggested that the development of warts is associated with the lignification of the cell wall.
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    ISSN: 1432-234X
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    Topics: Biology
    Description / Table of Contents: Zusammenfassung Agonistisches Verhalten, Samenübertragung und Spermatophorenmorphologie vonTarantula (Phrynus) palmata (Herbst) undHeterophrynus alces Pocock sind ähnlich wie bei anderen Arten der Familie Tarantulidae (Phrynidae). Anders ist das agonistische Verhalten vonTrichodamon froesi Mello Leitao. Die Palpen tragen an ihren Spitzen kleine Scheren und sind beim Männchen stark verlängert. Beim Kampf versucht jeder, die Tibien des 3. Beinpaares des Gegners zu ergreifen und dann nach hinten und hochzustemmen. Die Balz besteht aus Serien von vibrierenden und trillernden Bewegungen der Fühlerbeine und gelegent lichen Eingreifen des Weibchens; das Weibchen antwortet darauf mit charakteristischen Fühlerbeinbewegungen. Die komplizierte Spermatophore wird dadurch entleert, daß das Weibchen auf zwei Hebel drückt und dadurch die Samenpakete hochschnellen läßt. Diese werden dann in die Receptacula eingeführt und mit den hakenartigen Strukturen an den Gonopoden ergriffen und abgerissen. Ein Vergleich der bisher untersuchten Arten zeigt, daß das Paarungsverhalten keine charakteristischen Unterschiede bei verschiedenen Familien oder Gattungen zeigt. Aber die Spermatophoren zeigen familientypische Baueigenschaften.
    Notes: Summary Agonistic and mating beaviour and Spermatophore morphology ofTarantula (Phrynus) palmata (Herbst) andHeterophrynus alces Pocock are similar to those of other species of the Tarantulidae (Phrynidae). Males ofTrichodamon froesi Mello Leitao perform a different agonistic behaviour. Their pedipalps bear small apical chelae and are extremely elongate. During fighting, each male grasps the tibiae of the opponent's third legs and pushes them upward and backward. During mating, the male performs vibrating and tapping movements with its antenniform legs and occasionally grasps the female. The female responds by performing characteristic movements of her antenniform legs. The spermatophore is a complicated structure. It is emptied by the female's pressing down two levers which causes two sperm packages to become elevated. These are then grasped by the female's seminal receptacles and by two hook-like structures of her gonopods and finally pulled off the spermatophore. Comparison of the species so far studied shows that the mating behaviour, although it varies in different species, does not exhibit differences useful for taxonomic research. But the different spermatophores show family characteristic structural properties.
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    ISSN: 1432-234X
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    Description / Table of Contents: Zusammenfassung Die Strukturen des fingerförmigen Conus papillaris im Auge der ErzschleicheChalcides chalcides wurden licht- und elektronenmikroskopisch untersucht. Eine Abgrenzung zum Glaskörper hin fehlt. Das GefÄ\system gliedert sich in Arteriole, prÄkapillÄre GefÄ\e, Kapillaren und Venolen. Die Arteriole besitzt Endothelzellen mit kurzen FortsÄtzen und elektronendichten Cytosomen sowie eine locker angeordnete Muskelschicht. Die prÄkapillÄren GefÄ\abschnitte sind kurz und Ähneln im Aufbau der Arteriole. Die organellenreichen Endothelzellen der sehr langen Kapillaren weisen zürn GefÄ\lumen hin einen dichten Saum bis zu 1,2 Μm hoher, regelmÄ\ig angeordneter Mikrofalten auf, wÄhrend die basale ZelloberflÄche etwas weniger organisiert ist. In einer bindegewebigen GefÄ\scheide kommen PericytenauslÄufer vor. Die Venolen unterscheiden sich von der Arteriole durch eine grö\ere Zahl luminaler FortsÄtze und weniger Cytosomen im Endothel, sowie durch eine lockerer gebaute Muskelschicht. Im Interstitium finden sich Bindegewebszellen, Mastzellen und Pigmentzellen, deren Ultrastruktur beschrieben wird. Die zahlreichen marklosen vegetativen Nervenfasern enthalten auffallend wenige Schwannsche Zellen, deren Rolle formal z.T. von den Pigmentzellen eingenommen zu werden scheint. Die Nervenfasern dienen vermutlich teilweise der Innervation der zentralen GefÄ\e; andererseits kann erstmals in einem Conus papillaris auch eine Innervation von Pigmentzellen nachgewiesen werden. Die Befunde werden mit denen am Conus papillaris anderer Echsen und Pecten oculi von Vögeln im Hinblick auf strukturelle Gemeinsamkeiten zwischen beiden Organen verglichen. DerChalcidesconus entspricht in Form, GefÄ\architektur, Innervation und Mastzellgehalt dem typischen Echsenconus, wÄhrend die relative Kapillarvermehrung und die Gestaltung ihrer EndotheloberflÄche mit den VerhÄltnissen im Pecten oculi vergleichbar ist. Der Conus papillaris vonChalcides chalcides nimmt somit hinsichtlich seiner Ultrastruktur eine gewisse Mittelstellung zwischen Conus und Pecten ein. Vermutlich dient auch der Conus der ErnÄhrung der avaskulÄren Echsennetzhaut bzw. dem Austausch der intraokulÄren Flüssigkeit.
    Notes: Summary The conal process (conus papillaris) within the eye ofChalcides chalcides was studied by light and electron microscopy. The finger-like organ is not sharply bordered against the vitreous body. The vascular system consists of a central arteriole, precapillary vessels, capillaries and venules. The endothelial cells of the arteriole contain some luminal processes and many electron dense cytosomes. The arteriole is enveloped by a single layer of loosely arranged muscle cells. The precapillary vessels are short and in general resemble the arteriolar structure. The capillaries are forming long loops. Their endothelial cells are richly studded with cellular organelles, especially mitochondria and micropinocytotic vesicles. Their luminal surface is organized into numerous regularly arranged about 1.2 Μm high microfolds, whereas the basal area is developed in a similar but slightly decreased way. The capillaries are enveloped by a connective tissue vessel sheath and some pericyte processes. The endothelium of the venules differs from that of the arteriole in a higher number of luminal processes and lesser dense cytosomes. The muscle cells are loosely connected to each other forming up to 3 layers. The intervascular space of the conus is occupied by connective tissue cells, mast cells, and pigment cells. Connective tissue cells are represented by small rounded elements. Pigmented cells contain many mitochondria, some filaments, dense areas beneath the inner leaflet of the unit membrane, and they are covered in part by basement membrane-like material. Mast cells are richly supplied by specific granules, on which exocytotic processes could not be observed. The conus is innervated by numerous unmyelinated vegetative nerve fibers. Schwann cells are rare and in part seem to be replaced by pigment cells. The nerve fibers probably innervate the central vessels. In addition, for the first time an innervation of conal pigment cells is found. Our findings are compared to those of the conal process of other lizards and those of the pecten oculi within the bird's eye. Form. vascular architecture, innervation and content of mast cells resemble the situation in typical lizards' conal processes, whereas lengthening of capillary vessels and organization of the luminal surface of their endothelial cells correspond to those found in birds' pecten oculi. Therefore, the conal process ofChalcides chalcides based on its ultrastructure, seems to represent a position in the middle between the typical conus papillaris of lizards and the pecten oculi of birds. It is assumed that like the pecten the conal process serves to the nutrition of the avascular retina and/or the exchange of intraocular fluids.
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    Zoomorphology 87 (1977), S. 123-146 
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    Topics: Biology
    Description / Table of Contents: Zusammenfassung Das Appositionsauge des gro\en Kohlwei\lings,Pieris brassicae L. wurde elektronenmikroskopisch (TEM) untersucht. Der Bau eines Ommatidiums wird im Schema und Details anhand von Aufnahmen wiedergegeben. Der dioptrische Apparat besteht aus Cornea, Corneafortsatz und Kristallkegel. Der sensorische Teil ist aus neun Sehzellen zusammengesetzt. Die Retina ist mehrreihig. Vier distale einfache Sehzellen vom Typ I haben Anteil am distalen, vier proximale Sehzellen (Typ II) mit ihrem proximalen Hauptabschnitt am proximalen Rhabdomaufbau. Diese Rezeptortypen unterscheiden sich feinstrukturell. Die basale neunte Sehzelle besitzt keine oder stummeiförmige Microvilli, die keinen Anteil am gebÄnderten Rhabdom haben. Distales und proximales Rhabdom gehen ineinander über, unterscheiden sich aber morphologisch. Im distalen Rhabdom verlaufen die Rhabdomere in einer horizontalen Ebene nicht senkrecht zueinander und auch vielfach nicht exakt senkrecht zur optischen Achse des Ommatidiums; ihre Microvilli können gebogen sein und sich stellenweise über mehr als die HÄlfte des Rhabdoms erstrecken. Im proximalen Rhabdom sind die Microvilli gerade orientiert, überqueren aber auch verschieden weit das Rhabdom. Die Microvilliplatten benachbarter Rhabdomere sind proximal senkrecht zueinander orientiert. Das Rhabdom endigt basal an einer gro\en Tracheengabel, die als Tapetum wirkt. Fünf verschiedene Pigmentgranulatypen erscheinen in jedem Ommatidium. Jeder Pigmentgranulatyp ist einem bestimmten Zelltyp zugeordnet. Distale und proximale Sehzellen enthalten jeweils verschiedene Pigmente; die anderen drei Pigmenttypen sind auf zwei Haupt-, sechs Nebenpigmentzellen und sechs basale Pigmentzellen verteilt. Jeder distale Fortsatz der Nebenpigmentzellen enthÄlt Microtubulibündel und steht horizontal mit den FortsÄtzen benachbarter Nebenpigmentzellen in Verbindung. Au\erdem verlaufen auch in den Hauptpigmentzellen gebündelte Microtubuli parallel zur optischen Achse. Die Feinstrukturen werden beschrieben und ihre Bedeutung für die Funktion des Auges insbesondere im ultravioletten WellenlÄngenbereich wird diskutiert.
    Notes: Summary The apposition eye of the large Cabbage Butterfly,Pieris brassicae L., was investigated electronmicroscopically (TEM). Diagrams based on micrographs show details of the structure of an ommatidium. The dioptric apparatus is made up of cornea, corneal process, and crystalline cone. The sensory part consists of nine visual cells. The retina is tiered. Four distal visual cells (type I) participate in forming the distal rhabdome, the proximal part being formed by four proximal visual cells (type II) with proximal main sections. There are ultrastructural differences between these two types of receptors. The basal ninth visual cell forms, if any, only stubby microvilli that have no part in the formation of the ‘banded rhabdome’. There is no gap between the distal and proximal parts of the rhabdome, but the two parts differ morphologically. In the distal part the rhabdomeres do not interlock at right angles and are, for the most part, not exactly perpendicular to the optical axis of the ommatidium; their microvilli may be bent and sometimes extend more than halfway across the rhabdome. In the proximal rhabdome the microvilli are straight and parallel, though they too vary in extent across the rhabdome. The microvilli plates of neighbouring rhabdomeres interlock here at right angles. Basally the rhabdome ends at a large tracheal fork that acts as a tapetum. There are five different types of pigment granules in the ommatidium each belonging to a particular cell type. Distal and proximal visual cells each have one type of pigment; the other three types of pigment granules belong to two principal, six secondary, and six basal pigment cells, respectively. Each distal process of the secondary pigment cells contains microtubule bundles and is joined horizontally to the processes of neighbouring secondary pigment cells. Bundles of microtubules running parallel to the optical axis are found in the primary pigment cells, too. The ultrastructure is described, and its relevance for the eyes function, especially in the ultraviolet wavelength-range, is discussed.
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    Zoomorphology 86 (1977), S. 99-154 
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    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Es wurde die Entwicklungsgeschichte einiger Organsysteme vom Beginn der Segmentierung des Keimstreifens bis zum 1. Larvenstadium anLimulus polyphemus untersucht. Von besonderem Interesse erschien die Ausgestaltung metamerer Strukturen mesodermaler und ektodermaler Herkunft. Zwei Fragen standen im Vordergrund dieser Arbeit, einmal die umstrittene Abgrenzung der Prosoma-Opisthosoma-Grenze, zum zweiten die Entstehung des Syncephalon eines ursprünglichen Cheliceraten. Die Mesodermversorgung des Kopfes entspricht der anderer genauer untersuchter Cheliceraten, Es ist labrales Mesoderm und ein ausgedehntes prächelicerales Coelom vorhanden. Die prospektive Bedeutung des labralen Mesoderms ist die Ausbildung der schwachentwickelten eigentlichen Labralmuskulatur, vor allem aber die Bildung von Mundwinkelprotraktoren, rostralen Vorderdarmdilatatoren und Vorderdarmmuskulatur. Die prospektive Bedeutung des Prächelicerencoeloms liegt in der Bildung der Aorta anterior. Vermutlich ist die Entstehung des vorderen komplexen Dotterseptums ebenfalls auf den Einfluß dieses Prächelicerencoeloms zurückzuführen. Im Verlauf dieses Dotterseptums erfolgt eine bemerkenswerte Umkehrung der serial homolog entstehenden Anlagen mesodermaler Elemente. Die dorsale Extremitätenmuskulatur der Cheliceren gelangt gegenüber der dorsalen Extremitätenmuskulatur des folgenden, ja sogar des übernächsten Segmentes in eine caudal verschobene Position. Wahrscheinlich ist vergleichbares auch für die vordersten Suspensormuskeln des Endosternits der Fall. Im Nervensystem dieses Bereiches lassen sich ebenfalls eine Fülle von Besonderheiten nachweisen: Das Ganglion der Cheliceren besitzt nur eine vor dem Vorderdarm verlaufende Kommissur. Unabhängig von ihm entsteht in der Vorderdarmseitenwand ein Strang neurogenen Gewebes, der sich sekundär mit dem Chelicerenganglion verbindet und die sogenannten Rostralganglien, besser Stomodaealganglien oder Pharyngealganglien liefert, von denen aus, der Seitenwand des Vorderdarmes anliegend, sehr deutliche Nervenstränge dem Vorderdarm entlang ziehen (Stomodaealnerven nach Patten u. Redenbaugh, 1900). Einmalig innerhalb der Arthropoden ist die Versorgung des Vorderdarmes mit Muskulatur, die Beziehung zu sicher poststomodaeal angelegten Segmenten aufweist. Wenn auch deren Herkunft nur in wenigen Fällen geklärt werden konnte, so ist zumindest sicher, daß poststomodaeale Anteile des Primärsternits in den Vorderdarm eingebaut werden. Vor dem Chelicerenganglion liegt das von Johansson (1933) als Antennalganglion beschriebene Gebilde. Seine Bedeutung wird diskutiert. Rostral folgt ein weiteres Ganglion, welches aus den sekundär verschmolzenen Zentralkörperanlagen entsteht. Das Archicerebrum besteht aus den sehr spät entstehenden und mit zipfelförmigen Fortsätzen bis ins Epistom reichende Corpora pedunculata, dem sogenannten „Cerebralganglion“, welches die Sehzentren für die Medianaugen enthält und den seitlich angrenzenden optischen Ganglien. Das Gehirn vonLimulus ist durch Konzentrationsprozesse in medianer Richtung und damit verbunden einer Emporhebung von Zentralkörperganglion und Antennalganglion gekennzeichnet. Für das Verständnis der ungewöhnlichen Position des Komplexauges vonLimulus ist der Nachweis seiner caudalen Verlagerung wichtig. Das Herz entsteht aus den dorsalen Teilen der Coelome 5 bis 13. Das 7. Metamer wird ganz und das 8. zum größten Teil in das Prosoma einbezogen. Eine entscheidende Bedeutung der sich hierbei abspielenden Verlagerungsvorgänge kommt dem Dottersegment 6 zu. Im Opisthosoma verbleiben die Ganglien 9 bis 16. Die Ausgestaltung dorsoventraler Muskulatur macht die Anlage von insgesamt 18 Metameren wahrscheinlich. Die Zuordnung des Coeloms zu ektodermalen Strukturen (Seitenzähne und Seitenstachel des Opisthosomas sowie dorsalen Borsten wird diskutiert). Die anLimulus beobachteten gegenläufigen Gestaltungsbewegungen stellen eine Fülle von Fragen hinsichtlich der sie bewirkenden Faktoren.
    Notes: Summary The embryology of some organ systems from the beginning of the segmentation of the germ band to the first larval stage has been studied onLimulus polyphemus. The main concern was the formation of the metameric structures of mesodermal and ectodermal origin. Two question were mainly dealt with in this work: firstly, the controversal limitation between prosoma and opisthosoma; secondly, the development of the syncephalon of a primitive chelicerate. The mesodermal supply of the head agrees with other carefully studied chelicerates. There is a labral mesoderm and an expanded precheliceral coelom. The prospective importance of the labral mesoderm is the formation of the weakly developed labral muscles s.str., but mainly the development of the protractors of the mouth edge, the rostral dilatators of the esophagus, and the muscular sheath of the esophagus. The prospective significance of the precheliceral coelom is the formation of the aorta anterior. Presumably the development of the most anterior compound yolk septum is also due to the influence of this precheliceral coelom. In the course of this yolk septum a remarkable distortion of serially homologous developing anlagen of mesodermal elements occurs. The dorsal muscular system of the chelicera is placed caudal to the first ambulatory limb, even caudal to that of the second ambulatory limb. It might be the same for the anterior suspensor muscles of the endosternite. In the nervous system of this region quite a number of peculiarities can be found: The ganglion of the cheliceres has only one commissure which is in front of the esophagus. Independent of the cheliceral ganglion a line of neurogenic tissue develops in the lateral walls of the esophagus. Later this line comes into connection with the pilem of the cheliceral ganglion. This neurogenic line forms the so-called rostral, or better stomodaeal, ganglion and the very distinct stomodaeal nerves. Unique within the arthropods is the supply of the esophagus with dilatator muscles, which go to the base of the ambulatory legs 1 and 4 and the endosternite in close connection with the endosternocoxal muscles of those legs. The origin of most of the muscles is not quite clear but some show that poststomodaeal parts are incorporated in the esophagus. In front of the cheliceral ganglion we find the antennal ganglion first described by Johansson (1933). Its importance is discussed. An other ganglion follows further rostral which develops out of the secondarily united anlagen of the central body. The archicerebrum contains the corpora pedunculata which extends backward into the epistome, the so-called cerebral ganglion with the centers for the dorsomedian eyes, and laterally the optic ganglion. The brain ofLimulus is emphasized by the process of concentration in a median direction which brings the central body and the antennal ganglion in dorsal position. For an understanding of the unusual position of the complex eye ofLimulus, the demonstration of its caudal shifting is of importance. The heart develops out of dorsal parts of coelomic cavities 5 to 13. The seventh segment is completely amd the eighth segment in its main parts incorporated in the prosoma. The enlargement of the sixth yolk segment plays a dominant rôle within the process of shifting. Ganglions 9 to 16 stay within the opisthosoma. The development of the dorsoventral muscles shows the formation of 18 metamers. The relation between the coelomic and extodermal structures such as the spine, teeth, and apodemes of the opisthosoma is discussed. The shifting of material in a different or often antagonistic direction raises many question concerning the physiologic factors.
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  • 38
    ISSN: 1432-234X
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    Topics: Biology
    Description / Table of Contents: Zusammenfassung Die meisten Arten der Familien Dicranolasmatidae, Nemastomatidae, Ischyropsalididae und Sabaconidae besitzen als sekundäres männliches Geschlechtsmerkmal ein epidermales Drüsenorgan im Chelicerengrundglied, das oft in den Cephalothorax verlagert ist. Die Austrittsstellen für das Sekret liegen immer auf dem Grundglied entweder als Feld von Einzelporen (Porenplatte) oder als weitlumiger Einzelporus — die Porenplatte meist exponiert auf dorso-distaler Apophyse des Grundgliedes. Das komplexe Drüsenorgan besteht aus den eigentlichen Drüsenzellen und aus den Hüllzellen. Diese verknüpfen in wenigstens 2 Horizonten die Apices der Drüsenzellen mit den Sekretreservoiren und verankern sie an der Cuticula. Mehrere Drüsentypen treten auf: Zellen kurz und dann entweder auf die Apophyse der Cheliceren beschränkt oder wenn Apophyse fehlt, auf das Grundglied konzentriert (Typ 1;Dicranolasma, Ischyropsalis, Sabacon mit Ausnahmen). Lange und schmale Apophysen bieten keinen ausreichenden Platz für die Drüse; die Zellkörper verlagern sich in das Lumen des Grundgliedes oder/und in den distalen Teil des Cephalothorax. Extrem lange Zell-Apices ziehen zu den Hüllzellen (Typ 2;Mitostoma, Nemastoma). Von der Oberfläche in das Cheliceren-Lumen eingestülpte Porenplatte ergibt kurzen Kanal und punktförmige Austrittsstelle für das Sekret; Bau und Lage der Zellen wie Typ 2 (Typ 3;Carinostoma, Histricostoma). Extreme Verlängerung des Kanals bis in den Cephalothorax und bürstenförmige Anordnung der kürzeren Zellen rund um den Kanal mindert das Platzproblem auf andere Weise (Typ 4;Paranemastoma). Die Funktion der Drüse im Sozialverhalten (gustatorische Balz) erlaubt, in den Typen von l–4 jeweils konstruktive Effizienzsteigerungen zu erkennen. Damit ist es möglich, die Richtung des Evolutionsablaufes der Drüsenorgane abzulesen.
    Notes: Summary Most species of the families Dicranolasmatidae, Nemastomatidae, Ischyropsalididae, and Sabaconidae possess as a secondary male sex character an epidermal glandular organ which is situated in the proximal joint of the chelicerae, and the major parts of which are often shifted into the cephalothorax. The places of discharge of the secretion are always located on the proximal joint as a field of small pores or as one large pore. The field of small pores is usually exposed on a dorso-distal apophysis of the proximal joint. The complex gland consists of the gland cells proper and of the enveloping cells. They connect the apices of the glandular cells with the secretion reservoir with at least two layers, and join it firmly with the cuticle. Several types of glands occur. Cells are short and in this case restricted to the apophysis of chelicerae or if apophysis is absent they are concentrated in the proximal joint (type 1;Dicranolasma, Ischyropsalis, Sabacon with exceptions). From narrow apophysis the bodies of the cells are discharged into the lumen of the proximal joint or even in the distal part of the cephalothorax. In such cases extremely long cell apices join the enveloping glands in the apophysis (type 2;Mitostoma, Nemastoma). A short channel and a pointshaped discharging place for the secretion results from invagination of the pore field below the surface of the chelicerae; construction of cells as in type 2 (type 3;Carinostoma, Histricostoma). Extreme prolongation of the channel into the cephalothorax and lampbrush like grouping of the shorter gland cells diminishes the problem of accomodating the gland in a different way (type 4;Paranemastoma). The function of the gland in social behaviour (gustatory display) makes it possible to recognize enhanced efficiency in the different gland types from 1 to 4. This allows one to decide in which direction the evolution of cheliceral glands proceeded.
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    Zoomorphology 87 (1977), S. 155-164 
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    Description / Table of Contents: Zusammenfassung Die GenitalnÄpfe vonHydrodroma despiciens wurden mit dem Elektronenmikroskop untersucht. Feinstruktur und histochemisches Verhalten der Zellen der GenitalnÄpfe zeigen die Besonderheiten typischer Chloridzellen. Die GenitalnÄpfe der Sü\wassermilben müssen demnach als wichtige Orte der Osmoregulation angesehen werden.
    Notes: Summary The genital papillae ofHydrodroma despiciens were studied in the electron microscope. According to ultrastructural and histochemical results the cells of the genital papillae show specializations of typical chloride cells. The genital papillae of fresh water mites therefore are considered to be important sites of osmoregulation.
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  • 40
    ISSN: 1432-234X
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    Topics: Biology
    Description / Table of Contents: Resume La larve deFlustrellidra hispida, de type “cyphonaute”d, à vie pélagique, présente une paire de valves et des adaptations corrélatives. Elle possède douze types cellulaires épidermiques distincts qui font ici l'objet d'une description, analogues aux catégories cellulaires déjà connues chez les Alcyonidiidae; un seul de ces types cellulaires, le tissu suprapalléal, est indifférencié; il sera simultanément à l'origine de la gaine tentaculaire et de la partie ectodermique du premier polypide ancestrulaire. Contrairement aux autres larves de Cténostomes dont le développement a jusqu'ici été étudié, le tissu infracoronal, différencié, n'intervient pas dans la métamorphose.
    Notes: Summary The larvaof Flustrellidra hispida, model “cyphonaute,” with pelagic life, presents one pair of valves and correlative adaptations. It has twelve distinct, epidermic cellular types. They are described in this paper and are analogous to the cells types already known in the Alcyonidiidae; only one among these, the suprapalleal tissue, is not differentiated; it will simultaneously give the tentacular sheath and the ectodermic part of the first ancestrular polypid. Contrarily to the other larvae of Ctenostomes, the development of which has been studied up to now, the differentiated infracoronal tissue does not participate in the metamorphosis.
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  • 41
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    Zoomorphology 87 (1977), S. 237-246 
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    Topics: Biology
    Notes: Summary The topography of ocellar interneurons in the brain of the cabbage looper moth,Trichoplusia ni, was examined with the use of the cobalt infiltration and Timm's silver-sulfide intensification techniques. Two interneuron tracts are found in each half of the brain. One nerve tract is composed of 6–7 first order interneurons whose axons run to the ipsilateral side of the brain and terminate in the ventral protocerebrum. The other nerve tract is composed of 3 interneurons. Two of these are first order interneurons which project to the contralateral side of the brain where they terminate in the posterior protocerebrum. A third interneuron has processes connecting the two lateral ocelli and projects to both the ipsilateral and contralateral protocerebrum. Several small fibers are also present. Some of these extend to the lobula and the optic tubercule. A classification of ocellar interneurons for comparative study is proposed.
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  • 42
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    Zoomorphology 86 (1977), S. 287-296 
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    Topics: Biology
    Description / Table of Contents: Zusammenfassung Das positive allornetrische Wachstum von Pedipalpen und Laufbeinen vonT. froesi wird demonstriet. Die Zahl der Tibialdornen an der Tibia wird vom vierten Stadium an reduziert bis nur noch die Dornen übrigbleiben, die die terminale Greifschere bilden. Das 1. Beinpaar wächst isometrisch, und die Zahl der Fühlerbeinsegmente bleibt vom 2. Stadium an nahezu konstant. Es wird vorgeschlagen, die Damoniae Simon 1936 und Phrynichinae Simon 1892 in der Familie Phrynichidae zusammenzufassen.
    Notes: Summary Positive allometric growth of pedipalps and walking legs is demonstrated inT. froesi. From the fourth instar onward, the number of spines on the pedipalp tibia is reduced, and finally only those which participate in the formation of the pincers remain. The first legs grow isometrically, and the number of antenniform leg segments remains nearly constant from the second instar onward. It is suggested that the subfamilies Damoninae Simon 1936 and Phrynichinae Simon 1892 belong to a single family, the Phrynichidae.
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    Marine biology 40 (1977), S. 57-64 
    ISSN: 1432-1793
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    Notes: Abstract Observations were made on approximately 300 mating couples of Centropages typicus Krøyer. Mating behavior consists of 4 distinct stages: pre-copulation, spermatophore extrusion, copulation, and post-copulation. Successful copulation requires proper positioning of the spermatophore complex on the female urosome and is dependent upon precise movements and orientation of the male during the mating encounter. Sub-optimal mating encounters, resulting in the improper placement of the spermatophore complex, were observed and adaptations tending to reduce spermatophore wastage are discussed.
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  • 44
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    Notes: Abstract The use of an inert, radioactively labeled microsphere as a measure of particle accumulation (filtration activity) by Mulinia lateralis (Say) and Mytilus edulis L. was evaluated. Bottom sediment plus temperature and salinity of the water were varied to induce changes in filtration activity and thus enable us to judge the effectiveness of the particles as filtration indicators. The rate of loss of radioactivity observed in Mulinia lateralis held for several days after exposure confirmed that the particles are ingested by the organisms. The observed differences in particle accumulation and the ease of administration and measurement combine to make the use of these micropheres a valuable tool in studies dealing with particle distribution and accumulation.
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  • 45
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    Marine biology 40 (1977), S. 33-40 
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    Notes: Abstract Artificial substrata allow one to test a single factor in a complex environment. We wanted to determine whether surface particle size could regulate settlement and growth in marine macroalgae. Three grades of discrete monolayers of hard particles differing only in diameter (0.1 to 0.5 mm, 0.5 to 1.0 mm, 1.0 to 2.0 mm) were cemented to the surfaces of three quadrants on acrylic discs while the fourth was left smooth. All surfaces were painted with dissolved plastic to ensure chemical uniformity. At different times of the year, 25 plates were bolted directly to basement rock in the low intertidal zone on an exposed coast at the mouth of Narragansett Bay in Rhode Island (Fig. 1). Thirteen conspicuous species of macroalgae colonized the coated acrylic plates during the course of this investigation. Of these, the most abundant were Chondrus crispus, Corallina officinalis, Polysiphonia harveyi and Ulva lactuca, which were observed throughout the program. Initial settlement did not differ significantly among the experimental surfaces, but with time patterns in the distribution of these algal populations correlated with the surfaces beneath them. These differences were visually striking and not the same for each species. Most of the Chondrus crispus (79.5%) and U. lactuca (85.2%) appeared on the two largest particles, but only for C. crispus was the difference in populations within these grades significant (P〈0.05). Populations were considerably smaller on the smallest grade (20.1 and 13.8% respectively), and on the smooth quadrants only a few individuals of these two species appeared (0.5 and 1.0%). The number of plants of P. harveyi, on the other hand, did not differ on the three particle sizes tested, but on the smooth surfaces only 2.9% appeared. Corallina officinalis showed optimal development on the smallest grade (44.8%). On smooth surfaces, where 8.4% of its population was observed, no upright articulated portions developed. The season during which the substrata were introduced altered the patterns of development. C. officinalis was the first macroalga to be seen in late spring, but on plates set out in the fall this species did not appear until the following late spring. P. harveyi covered some discs in fall, spring and summer, and on these surfaces Chondrus crispus was delayed up to 1 year. By the end of the experimental period (15 months), C. crispus was the most conspicuous macroalgal species on most of the plates.
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    Marine biology 40 (1977), S. 41-49 
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    Notes: Abstract The relationship between the osmotic pressures of the blood and the ambient medium was determined for 4 species of bivalve molluscs whose habitats represent distinct salinity regimes within the range from fresh to full seawater. These organisms included 3 corbiculids: Corbicula manilensis (freshwater); Polymesoda caroliniana (brackish-water); Pseudocyrena floridana (marine) and 1 unionid: Elliptio lanceolata. On the basis of the data and similar measurements from the literature, we have placed the molluscs into 5 categories: marine stenohaline, marine euryhaline, oligohaline, fresh-water euryhaline and freshwater stenohaline. Marine stenohaline and euryhaline species are osmoconformers. They differ only in the size of the free amino acid pool available for intracellular volume regulation, and thus in the range of salinities that they tolerate. Oligohaline species tolerate salinities from seawater down to freshwater; they not only possess a large capacity for volume regulation, but can also osmoregulate below 3‰ S. Freshwater species also osmoregulate below 3‰ S, but they are usually limited to salinities below 2‰. Presumably, in evolving from the marine to the freshwater habit, they have lost the ability to volume-regulate in response to hyperosmotic stress. We propose that the varying physiological characteristics underlie the well-known relationship that species abundance declines from both freshwater and full seawater to a minimum between 3 and 5‰ S. We have related this species minimum to physical-chemical discontinuities in the ionic composition of seawater which are, again, reflected in the physiological mechanisms of the molluscs.
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    Marine biology 40 (1977), S. 81-86 
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    Notes: Abstract Female shiner perch, Cymatogaster aggregata Gibbons, initiate and display reproductive behaviors that are similar to behaviors shown by males during their reproductive cycle. No consistent quantitative differences in behavior are found when females in three reproductive states are compared.
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    Marine biology 40 (1977), S. 75-80 
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    Notes: Abstract Pacific hake [Merluccius productus (Ayres)], migrating northward along the California coastline during summer, encounter the southwesterly flowing plume of the Columbia River. Radioactive 65Zn associated with the plume waters is taken up by the migrating hake. Smaller fish reflect this contamination earlier than larger fish. Zinc-65 specific activities increase toward the north as far as 46°N, off the mouth of the Columbia River, and then decline northward along the coast of Washington.
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    Marine biology 40 (1977), S. 65-74 
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    Notes: Abstract The acute toxicities of several oil dispersants to the larvae of haddock, herring, lemon sole, pilchard, plaice and sole were examined, the type and aromatic content of the solvent being the main factors influencing the toxicity. Newer (“second generation”) dispersants had much lower toxicities. Ageing of dispersant solutions led to a decrease in toxicity, which could be related to loss of aromatic compounds from solution. Temperature and salinity had only slight influence on toxicity. For all dispersants, differences of susceptibility between species were less than differences at different ages within a species. The larvae of all species showed a similar susceptibility when newly hatched, and susceptibility increased throughout the yolk-sac stage. The transition period from yolk reserves to an external food supply was most critical, for once larvae had established feeding, resistance increased until metamorphosis. The dispersants appeared to act largely as physical toxins causing, initially at least, a reversible narcosis. The implications of the results are discussed in relation to the use of dispersants at sea.
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    Marine biology 40 (1977), S. 87-94 
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    Notes: Abstract The distribution of some microbial parameters was studied at 3 stations in the Central Baltic Sea (Bornholm Basin, BB; Danzig Deep, DD; and Gotland Deep, GD) during May 1976. The following analyses were performed: total bacterial numbers and biomass, viable counts and maximum uptake velocity (V max) of glucose. The values found for thesurface, samples were, total bacterial counts: 0.6x106 (BB); 1.7x106 (DD); 0.4x106 (GD) cells/ml; bacterial biomass: 1.9 μg C/l (BB); 6.9 μg C/l (DD); 1.6 μg C/l (GD); viable counts: 0.37x103 (BB); 17x103 (DD); 0.4x103 (GD) counts/ml; V max: 0.01 μg glucose-C/l (BB), 0.06 μg glucose-C/l (DD); 0.01 μg glucose-C/l (GD). The relatively high microbial numbers and activities of the Danzig Deep may be associated with the fertilization of the area by the River Vistula. The vertical distribution of the microbial parameters in the Bornholm Basin and Danzig Deep showed high values both in the top layer (0 to 20 m) and in the deep layer (〉40 m). In the intermediate layer, however, the values decreased significantly. It is suggested that the high values of the microbial parameters at depth are caused by at least two major processes during the inflow of North Sea water into the deep layers of the Baltic Sea: (1) the North Sea water may already have contained high numbers of bacteria; (2) during the inflow, the high concentrations of bacteria normally located at the sediment-water interface are distributed throughout the whole deep layer by mixing.
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    Notes: Abstract A simple tide-simulation apparatus was used to investigate the influence of emersion and temperature on the intertidal growth of Padina japonica Yamada in both the juvenile and adult growth phases. The upper zonation limits are not determined by the sensitivity of any particular growth phase, since all phases show the same emersion tolerance limits. The species grows best when continuously submerged, and growth rates decrease with increasing emersion up to a clear upper zonation boundary. High temperature reduces the emersion tolerance and is therefore an important factor in tropical intertidal zonation.
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    Marine biology 41 (1977), S. 7-17 
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    Notes: Abstract Bacterial sulfate reduction was demonstrated in the oxidized surface layers of a coastal marine sediment using a radiotracer technique. The obligate anaerobic process takes place within reduced sediment pellets of 50 to 200 μm diameter. The H2S produced diffuses out into the interstitial solution and is oxidized before any detectable accumulation takes place. This microniche structure explains the presence of sulfate-reducing (Desulfovibrio spp.) and sulfide oxidizing (Beggiatoa spp.) bacteria and of ferrous sulfide and pyrite in the oxidized sediment. Sulfate reduction was also demonstrated within detrital particles experimentally decomposed in oxic seawater or sediment. The limiting conditions for the maintenance of a reduced microniche within an oxic environment is discussed in terms of a theoretical model.
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    Marine biology 41 (1977), S. 39-48 
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    Notes: Abstract Data on the amount of organic detritus within the particle size fraction 1 to 150 μ are presented for the Western Kiel Bight. Grouped into a mixed surface layer and a stratified lower layer in accordance with the main hydrographic features of the Western Baltic Sea, the rounded-off values show a seasonal variation between 100 and 600 mg m-3 expressed as dry weight of organic matter. The overall average for both layers is about 200 mg m-3. Organic detritus thus comprises more than 40% of total organic matter in the above size class, which is the class most easily accessible to the relatively small filter-feeders in this area. Attempting to trace the origin of organic detritus, a positive correlation to phytoplankton standing stock was found in some cases, suggesting the predominance of autochthonous detritus. Proceeding from the assumption that pelagic filter-feeders select their food mainly by size and not by taste, it is concluded that organic detritus plays an important role as a supplementary food source, being ingested together with phytoplankton and small nonmotile heterotrophs. The nutritive value of detritus is increased by the adsorption of dissolved organic matter and above all through the subsequent colonization by bacteria, which utilize the dissolved substances. Detritus particles serving as a substratum for bacteria thus form a means whereby dissolved organic substances reenter the food chain. The ingestion of detritus by filter-feeders is, therefore, thought to be instrumental in increasing the effectivity of energy transfer from the primary to the secondary food-chain level.
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  • 54
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    Marine biology 41 (1977), S. 53-58 
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    Notes: Abstract Mytilus edulis L., collected from a mid-tide level on the shore, showed rhythmic changes in mantle fluid pH, crystalline style pH, style length and total protein, and in the amylase activity in the digestive gland. These changes were correlated with the changes in tidal height. Style size may be related to extracellular digestion in the stomach. Style size and amylase content of the style were not significantly correlated with each other. The changes in amylase activity in the digestive gland confirmed the existence of a tidal rhythm for intracellular digestion in M. edulis.
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  • 55
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    Marine biology 41 (1977), S. 79-88 
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    Notes: Abstract The net uptake of zinc by the common mussel Mytilus edulis (L.) has been investigated under different natural and artificial salinity stresses. The effects of stable and fluctuating salinities on the uptake of zinc by the mussel are discussed in terms of three possible modes of action. Under certain highly-stressful conditions, salinity may affect the uptake of zinc by the mussel. This factor should be considered when the mussel is used as an indicator of environmental pollution by zinc in estuarine areas, or spurious conclusions may result.
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  • 56
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    Notes: Abstract The effect of temperature on the growth and proliferation of two marine microorganisms, the toxigenic dinoflagellate Gymnodinium breve, and a potential bio-control organism, the blue-green alga Gomphosphaeria aponina, was determined by culturing the organisms in thermal gradients established by heating and cooling the opposite ends of an aluminum bar that had been adapted to hold culture tubes. Gradients were linear and stable for the duration of each trial. There was no relationship between variations in light and growth of the organisms. Gymnodinium breve showed optimum growth at 22°C, and proliferated over a range of temperatures (17° to 30°C). Below 17°C cultures of G. breve declined in growth, and at 4°C the organisms died within 5 h. Above 31°C there was rapid decline in viability of cells, and at 33.5°C the organism died within 24 h. Gomphosphaeria aponina showed optimum growth between 24° and 29°C, with a maximum at 27°C. Growth at temperatures greater than 31°C was minimal, but the organism survived. Limitation may be due to repression of the bio-synthesis of an iron-transport compound.
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  • 57
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    Notes: Abstract Samples of various tissues and organs from healthy, sick and dead harbour seals (Phoca vitulina) from the North German Waddensea collected during the years 1974–1976 were analysed for copper, zinc, total mercury, cadmium lead, and organochlorine pesticide residues (PCB, DDT, Lindane and Dieldrin). The investigations were carried out in order to increase our knowledge about the actual degree of heavy metal and organochlorine pesticide accumulation in these animals. The study was also directed towards a comparison of healthy and sick young seals and those found dead for a possible relation between the condition and concentration of polutants in the organs. There was great variation within all series of compounds investigated, but in general the analytical data obtained indicated that high amounts of heavy metals and organochlorine pesticides can be present even in young seals. An age-specific increase in the mercury and cadmium content in liver samples could be demonstrated. The results are compared with data published by British and Dutch authors for other North Sea regions, and with a few exceptions, no significant differences can be established: cadmium (kidney) and DDT (blubber) contents in areas off the British coast are usually higher than corresponding values for seals from the German coast. There was no clear evidence that the concentrations of any of the compounds investigated had negative effects on the health of the seals. However, possible combined effects cannot be excluded.
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  • 58
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    Marine biology 41 (1977), S. 127-140 
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    Notes: Abstract A comprehensive study of the fouling organisms encountered at the New Mangalore Port at Panambur and the Fish Landing Jetty on the Nethravati-Gurpur estuary near the old Mangalore Port, India, was made. Barnacles, oysters, bryozoans, polychaetes and hydroids are the dominant groups of foulers encountered in this region. Barnacles are by far the most important foulers. Distinct seasonal abundance in settlement was noticed in the different groups. The major peak settlement of barnacles occurs in November and December. Continuous settlement of this group in the harbour indicates the presence of larvae throughout the year in the marine locality. The absence of freshly settled spat in the estuarine locality shows that these larvae do not foul structures in the Fish Landing Jetty during the monsson period. The pattern of oyster settlement indicates that the spat of Crassostrea madrasensis and c. cucullata settle during January, March, May and October in this region. This group remains in the fouling community throughout the year. Only typical marine bryozoans are harboured in abundance in the fouling community. Polychaetes occur in great numbers during April and December.The differences in the quality and quantity of the fouling communities are controlled by their breeding periodicity,seasonal fluctuations in the hydrographical conditions, and the species composition of the sedentary community of this region.
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  • 59
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    Marine biology 41 (1977), S. 147-152 
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    Notes: Abstract The crested blenny Anoplarchus purpurescens occurs intertidally in the Puget Sound area (USA), where it is subjected to substantial variation in temperature. A study of a polymorphic esterase in A. purpurescens has revealed a latitudinal cline and a correlation of allelic frequencies with summer water temperature. This finding agrees with previous results for a lactate dehydrogenase polymorphism in A. purpurescens, suggesting a pervasive genetic adaptation to temperature in this species. For each of these enzymes, comparisons within and between two species of Anoplarchus andicate an association between heterozygosity and temporal variability of the thermal environment.
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  • 60
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    Marine biology 41 (1977), S. 179-184 
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    Notes: Abstract In a study of the toxicity of mercury, silver, copper, nickel, and zinc to larvae of the American oyster Crassostrea virginica and hard clam Mercenaria mercenaria, the concentrations at which 5% (LC5), 50% (LC50), and 95% (LC95) of the larvae died were determined, as well as growth at the LC5 and LC50 values. The order of toxicity for oyster larvae was Hg〉Ag〉Cu〉Ni, and for clam larvae Hg〉Cu〉Ag〉Zn〉Ni. Growth of larvae of both species, with the exception of clam larvae in nickel-treated water, was not reduced at the LC5 values, but was markedly reduced at the LC50 values.
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  • 61
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    Notes: Abstract Specimens of Chlamys opercularis, Modiolus modiolus, Mytilus edulis, Crassostrea gigas, Scrobicularia plana and Mya arenaria were exposed to both gradual (sinusoidal) and abrupt (square-wave) salinity fluctuations and measurements made of osmotic, Na+, Mg2+ and Ca2+ concentrations in the hemolymph and where applicable in the mantle fluid. In both sinusoidal and square-wave regimes fluctuating between 100 and 50% seawater (100%=ca. 32‰ S), the hemolymph Na+, Mg2+, Ca2+ and osmotic concentrations followed the concentrations of the external medium in Chlamys opercularis. The hemolymph and mantle fluid osmotic Na+, Mg2+ and Ca2+ concentrations of Modiolus modiolus, Mytilus edulis, Crassostrea gigas and S. plana followed those of the external medium as long as the molluscs' shell valves remained open. There were no changes in the ionic or osmotic concentrations of the hemolymph or mantle fluid of any of these species during periods of shell-valve closure. The hemolymph osmotic, Na+ and Mg2+ concentrations of wedged-open Modiolus modiolus, Mytilus edulis, C. gigas and S. plana followed those of the external medium. Hemolymph Ca2+ concentrations showed a damped response in C. gigas and Mytilus edulis. The hemolymph osmotic, Na+, Ca2+ and Mg2+ concentrations of Mya arenaria fluctuated in a similar manner to the external medium, but were damped. Wedged-open Mytilus edulis exposed to fluctuating salinity and supplied with a constant supply of 10 mM Ca2+ showed greater changes in hemolymph ionic and osmotic concentrations than M. edulis exposed to the same salinity fluctuation without a constant Ca2+ supply. Chlamys opercularis and Modiolus modiolus survived in a 50% seawater minimum sinusoidal salinity fluctuation for 10 days; wedged-open M. modiolus survived only 3 days. Burrowing had no effect on the osmotic, Na+, Mg2+ or Ca2+ concentrations of the hemolymph of Mya arenaria or S. plana exposed to fluctuating salinities. All of the species studied were shown to be osmoconformers.
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  • 62
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    Marine biology 41 (1977), S. 191-197 
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    Notes: Abstract Studies were made of some carotenoids extracted from Axinella verrucosa (O. schmidt) (Porifera: Demospongiae), a species which occurs in the Gulf of Naples. α-carotene, renieratene, isorenieratene, and an unknown isomer of renieratene have been isolated.
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  • 63
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    Marine biology 41 (1977), S. 185-190 
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    Notes: Abstract The results of tagging studies conducted to determine the relationship between estuarine (juvenile) populations and adults at sea suggest that maturing Metapenaeus macleayi leave the estuaries and move along the coast in a northerly direction; the longest migration recorded was 120 km, but most prawns appear to disperse in shallow water (〈40 m) within about 70 km of their juvenile habitat. There are approximately 60 estuarine populations of M. macleayi in south-east Australia; the geographical range of prawns emigrating from most estuarine populations overlap (at sea) to some degree with that of adjacent or nearby populations, but there is little or no overlap between any two of the 6 major populations. The mixing of individuals from a major population and from nearby smaller populations is negligible for the purposes of fisheries management, hence the prawns in each of the major estuarine populations and the adults in the coastal area north for about 70 km may be regarded as a unit stock.
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  • 64
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    Marine biology 41 (1977), S. 199-212 
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    Notes: Abstract For field samples, regression analyses of plots of chemically determined particulate organic carbon on chlorophyll are often employed to estimate the algal carbon-to-chlorophyll ratio (F) in the presence of appreciable amounts of nonalgal particulate organic carbon. Spurious results will be obtained, however, if the temporal rate of change of the algae or the nonplant matter reverses its sign during the sampling interval and the samples cannot be ordered correctly in time or space. Previously recognized sources of bias inherent in the chemical approach are also discussed. The great uncertainty of our present knowledge of F is pointed out. It is shown that the concentration of microscopically visible, nonliving particles in the sea isnot known. Renewed studies are suggested as a means of improving on the chemical approach to determining F. The general argument holds for the ratios of nitrogen (particle volume, etc.)-to-chlorophyll, carbon (nitrogen, particle volume, etc.)-to-ATP, and similar conversion factors.
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  • 65
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    Notes: Abstract Changes in hydrolytic, respiratory,catabolic and lipid biosynthetic activities depend at least in part on successional changes in the microfloral populations of allochthonous plant litter incubated in a semi-tropical estuary. Initial colonization is by populations which have a high content of muramic acid relative to the adenosine triphosphate (ATP) and which are progressively displaced by a microflora with a lower ratio of muramic acid to ATP. Scanning electron micrography of the plant-litter microflora shows a succession of forms, with an initial bacterial colonization and its progressive displacement by more complex forms. Estimates of the microbial mass and the rates of phospholipid synthesis suggest that the detrital microflora has a relatively slow growth rate compared to its growth potential.
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  • 66
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    Notes: Abstract The magnitude and physiological characteristics of biological nitrogen fixation have been studied in the oligotrophic waters of the North pacific gyre. The filamentous blue-green algae Trichodesmium spp. and Richelia intracellularis were the important nitrogen-fixing phytoplankton. Most of the nitrogen fixation occurs in the upper 40 m of the water column, with detectable fixation as deep as 90 m, which corresponds to about the 1 % light depth. There was no evidence of photoinhibition of nitrogen fixation, although CO2 reduction was depressed slightly at the highest light levels. The rate of nitrogen fixation in the water column varied throughout the day, being highest in mid-morning and in late afternoon. Relatively high fixation rates were also found during periods of darkness. Elevated oxygen concentrations had a marked inhibitory effect on rates of nitrogen fixation, a pO2 of 0.4 atm causing a 75% inhibition. Data from studies of nitrogen fixation and assimilation rates of 15N-labelled nitrate, ammonium, and urea indicate that nitrogen fixation furnished about 3% of the total daily fixed nitrogen requirement for phytoplankton growth. Studies with isolated colonies of Trichodesmium spp. indicated that 100% of their nitrogen requirement was met by nitrogen fixation. Chemical composition of the Trichodesmium colonies showed that the C:N ratio was 4.1 and that their phosphorus content relative to carbon or nitrogen was much lower than that of the total particulate material in the water column. Elevated ratios of carbon: adenosine triphosphate (ATP) also suggest that phosphorus deficiency may be limiting the growth of Trichodesmium. The magnitude of nitrogen fixation in the gyre is seasonally dependent, with high rates in late summer and autumn. At these times the water column is stratified, with phosphate and nitrate barely detectable in the upper 100 m. Our data suggest that during these months of stratification, biological fixation of nitrogen amounts to about 33 μg-at N/m2/day.
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  • 67
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    Notes: Abstract Herbivorous zooplankton species (Calanus plumchrus, Paracalanus parvus and Euphausia pacifica) and carnivorous species (Parathemisto pacifica and Pleurobrachia pileus) collected from Saanich Inlet, British Columbia, Canada, were maintained in the laboratory under fed and starved conditions. Respiration rate and excretion rates of ammonia and inorganic phosphate were measured successively on the same batch populations of each species in different feeding conditions. Respiration rate remained at a constant level or increased during the feeding experiment but decreased progressively in starved individuals. Herbivorous, but not carnivorous, species showed a rapid decrease in both excretion rates for the first few days of an experiment irrespective of feeding conditions. However, the general level of excretion rates of fed specimens was higher than that of starved ones. The O:N, N:P and O:P ratios were calculated from respiration, ammonia excretion and phosphate excretion and discussed in relation to metabolic substrates of animals during the experiment. A marked difference was shown in the O:N ratio between fed hervivores (〉16) and fed carnivores (7 to 19), suggesting highly protein-oriented metabolism in the latter. One unknown factor causing variation in excretion rates is speculated to be the physiological stress on animals during sampling from the field. It is suggested that the laboratory measurement of realistic excretion rates of zooplankton is difficult owing to their large fluctuations, but this is not the case with respiration rate.
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  • 68
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    Notes: Abstract We have monitored the incorporation of 3H-glycine into, and the excretion of, soluble tissue and extrapallial fluid proteins in the hardshell clam Mercenaria mercenaria in an attempt to follow some of the metabolic events that occur antecedent to shell deposition. After incubating at 20°C for 48 h, clams were killed and the distribution of incorporated and unincorporated tritium in seawater, mantle fluid, hemocoelic-tissue fluid, extrapallial fluid and tissue was determined. Most of the incorporated tritium was in the insoluble tissue proteins. Much more incorporated tritium was found in the hemocoelic-tissue fluid fraction than in the extrapallial fluid. We assume that most of the radioactivity we followed was due to free or incorporated radioactive glycine. The ratio of 3H-protein to 3H-glycine was greater in the extrapallial fluid than in the hemocoelic-tissue fluid, suggesting either protein secretion into or glycine removal from the extrapallium. We also observed that both 3H-protein and 3H-glycine concentrations were higher in the mantle fluid than in the external sea water, although the ratios of 3H-glycine to 3H-protein in these two fluids were not different.
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  • 69
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    Notes: Abstract Sheets of mantle tissue from above the mantle line of Mercenaria mercenaria were incubated for 2, 6 and 20 h at 20°C in 50 μCi 3H-glycine in 50 ml artificial seawater. Incorporation of tritium into soluble proteins excreted by the mantle and into tissue proteins was followed. The excretion of soluble protein continued throughout the experiment; the proportion of incorporated label excreted reached 17% by 20 h. The initiation of excretion of labelled protein seemed to lag 60 to 70 min behind the initiation of protein synthesis. Protein synthesis by the mantle contributed to proteins of the extrapallium and mantle chambers and, thus, may be involved in synthesis and regulation of proteins involved in the shell-formation process.
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  • 70
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    Marine biology 41 (1977), S. 269-273 
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    Notes: Abstract Rapid uptake and slow loss of Hg will result from short exposures of some organisms to this metal, due to the transformation of Hg to a slowly exchanging form within the organisms. The extent of the difference between exposure time and depuration time will depend upon the rate of transformation during uptake. For the polychaete worm Neanthes succinea and the shrimp Palaemon debilis such transformations are extremely rapid. The exchange of Hg from the slowly exchanging compartment is similar among a wide variety of species. Thus, interspecies differences in susceptibility to Hg may be determined by differences in biochemical transformation rates and physiological permeability to the metal.
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    Marine biology 41 (1977), S. 263-267 
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    Notes: Abstract Plutonium contents of various species of molluscs sampled from several sites along the French coast were measured in order to reveal any distributional patterns of the plutonium levels. The influence of the La Hague nuclear fuel reprocessing plant was apparent in the immediate proximity of the waste-disposal outfall (Ecalgrain Bay), and to a lesser degree in an oyster farming center situated about 50 km east of the Bay of Ecalgrain (St. Vaast-la-Hougue). Plutonium concentrations in molluscs from the remaining sites were quite comparable to levels that have been measured in similar species subject only to plutonium derived from atmospheric fallout. All molluscs, except those from Ecalgrain Bay, displayed higher levels of plutonium in the shell than in the soft parts, a finding in agreement with similar studies which have been reported recently. However, those individuals sampled from the vicinity of the outfall consistently displayed shell: soft parts plutonium ratios of less than 1. This difference may reflect different physico-chemical forms of this isotope present at the different sampling stations. With the exception of Crepidula fornicata shell, the tissues of filter-feeding molluscs do not appear to concentrate plutonium above the level found in other types of molluscs.
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    Marine biology 41 (1977), S. 275-279 
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    Notes: Abstract An investigation of the osmoregulatory capabilities of two portunid crabs, Callinectes sapidus and C. similis, was conducted to determine if their differences in distributional patterns were reflected in their capacity to adjust physiologically to changes in salinity. After acclimation to 5, 20 and 35‰ S, measurements of hemolymph and muscle concentrations of Na+, Cl- and K+ and muscle-free amino acids indicated that C. sapidus is a better osmoregulator at low salinity than C. similis, while both species osmoregulate equally well at high salinity. This difference in osmoregulatory capacity corresponds well with their distribution in coastal-plain estuaries.
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    Marine biology 41 (1977), S. 281-286 
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    Notes: Abstract Uca musica terpsichores males sometimes dislodge their neighbors and fill in their burrow entrances with sand. Field observations and marking of individual burrows were used to determine the frequency of this activity as well as the sex and behavior patterns of the actors involved. Burrow filling is performed only by adult males which will display later on in the low-tide period. It is directed toward neighbors of both sexes. However, significantly more male neighbors were dislodged (46%) than female neighbors (28%) for distances up to 25 cm from the aggressor's burrow. For both sexes, the frequency of burrow filling increased significantly the closer they burrowed to displaying males. From these results, it is suggested that burrow filling is a primary means by which U. musica terpsichores males establish and maintain their territories, which they use for display purposes. A description of the burrow-filling behavior is also given.
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    Marine biology 41 (1977), S. 287-291 
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    Notes: Abstract The food and feeding habits of Anguilla anguilla L. in Lake Manzalah (Egypt) have been studied. Analysis of stomach contents revealed that eels alter their type of diet as they grow. Their feeding rate varies also with season, size and environmental temperature. A negative correlation was found between length and feeding index of A. anguilla.
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    Marine biology 41 (1977), S. 307-315 
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    Notes: Abstract A carbon-14 assimilation method was used to determine action spectra and photosynthesis versus irradiance (P versus I) curves of natural populations of phytoplankton and zooxanthellae from a coral reef fringing Lizard Island in the Australian Barrier Reef. The action spectra were related to the phytoplankton species composition. The curves showed shade adaptation in phytoplankton from deeper waters and in the zooxanthellae. Rates of photosynthesis of zooxanthellae were shown to be highly but variably dependent on their host organisms. Photosynthetic production by zooxanthellae was about 0.9 gC m-2 day-1, which is about three times higher than phytoplankton production in the waters close to the reef.
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  • 76
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    Marine biology 41 (1977), S. 293-305 
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    Notes: Abstract The rate of utilization of inorganic carbon (C) and phosphate (P) by phytoplankton and bacteria in the Rhode River estuary has been estimated using liquid-emulsion autoradiography during four times of the year. Metabolic activity of phytoplankton was estimated by calculating silver grains above individual species. From these counts, the relative C and P uptake rates of individual species per unit of biomass and per volume of water were estimated. Examination of the autoradiograms showed that the metabolically most active, algae were smaller than 10 μm. Both C and P were paken up by these smaller species at a higher rate than their proportion of the total biomass per volume of water would indicate. Uptake of C and P per unit of cell volume varied within a species and among the various phytoplankton at the different seasons of the year. Metabolic activity of planktonic bacteria in safranin-stained autoradiograms was also estimated by counting bacteria with associated grains and cells without grains. The ratio of 33p-labeled to unlabeled bacteria was highest in November. This high metabolic activity of bacteria in November corresponded with high P uptake rates of the phytoplankton at that time. Throughout this study, only 28 to 42% of the total phytoplankton biomass was metabolically active and, 63 to 85% of the bacteria.
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  • 77
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    Notes: Abstract The results of a year-long study in which epibenthic invertebrates were collected monthly from seagrass (Thalassia testudinum) meadows along the Caribbean coast of Panamá and the Panamá Canal Zone are described in this paper. Differences in species composition and abundance among sites were primarily due to the proximity of surrounding habitats, especially coral reefs, which contain a number of species that utilize the seagrass meadows. In contrast to many previous characterizations of tropical marine habitats, important seasonal fluctuations in both species number and abundance took place at each of the sites. Data on breeding activity among several species of decapod crustaceans indicate year-round reproduction, although considerable seasonal differences occur in the percentage of ovigerous females. These interspecific differences in observed reproductive output may be explained by differences in life-cycle length, a factor not often considered in discussions of seasonal breeding patterns in tropical marine invertebrates. Overall species composition was qualitatively similar to that reported in comparable studies of tropical and subtropical seagrass meadows elsewhere, although caridean shrimp and xanthid orab species were reduced in number and total abundance were much lower than in previous studies.
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    Marine biology 41 (1977), S. 349-353 
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    Notes: Abstract A procedure for the determination of chitinase activity was adapted for the seawater environment. Preliminary data indicate that the controlled bacterial environment within the digestive tracts of marine fishes and possibly other marine animals plays a significant role in the decomposition and recycling of chitin. It is estimated in the stomachs of a single population of Enophrys bison (buffalo sculpin) of 1×105 fish that ca. 16 metric tons of chitin could be decomposed annually.
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    Marine biology 41 (1977), S. 355-360 
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    Notes: Abstract The occurrence of chitinase in the stomach contents of Enophrys bison and Platichthys stellatus was investigated. The highest chitinase activity and the greatest percentage of chitinoclastic bacteria in relation to the total bacterial flora were associated with fish whose stomach content was composed primarily of chitinous animals. Stomach contents lacking visible chitin possessed low or no detectable levels of chitinase activity and few chitinoclastic bacteria. Juvenile E. bison treated with chloramphenicol to remove their indigenous bacterial flora had no detectable level of chitinase in their stomach contents while non-treated juveniles showed inducible chitinase activity, indicating the bacterial origin for the chitinase.
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    Notes: Abstract Demersal zooplankton, those plankton which hide within reef sediments during the day but emerge to swim freely over the reef at night, were sampled quantitatively using emergence traps planced over the substrate at Lizard Island Lagoon, Great Barrier Reef. Densities of zooplankton emerging at night from 6 substrate types (fine, medium, and coarse sand, rubble, living coral and reef rock) and from 5 reef zones (seaward face, reef flat, lagoon, back reef, and sand flat) were determined. A large population of nocturnal plankton including cumaceans, mysids, ostracods, shrimp, isopods, amphipods, crustacean larvae, polychaetes, foraminiferans and copepods are resident members of the reef community at Lizard Island. The mean density of plankton emerging throughout the reef was 2510±388 (standard error) zooplankton/m2 of substrate. Biomass averaged 66.2±5.4 mg ash-free dry weight/m2 of substrate. Demersal zooplankton exhibited significant preferences for substrate types and reef zones. The highest mean density of zooplankton emerged from coral (11,264±1952 zooplankton/m2) while the lowest emerged from reef rock (840±106 zooplankton/m2). The density of demersal plankton was six times greater on the face than in any other zone, averaging 7900±1501 zooplankton/m2. Copepods dominated samples collected over living coral and rubble while foraminiferans, ostracods and decapod larvae were most abundant from sand. Plankton collected with nets at night correlated only qualitatively with plankton collected in emergence traps from the same location. Although abundant, demersal plankton were not numerous enough to meet the metabolic needs of all corals at Lizard Island Lagoon. Demersal plankton appear especially adapted to avoid fish predation. The predator-avoidance strategies of demersal plankton and maintenance of position on the reef are discussed. Our results indicate that much of the zooplankton over coral reefs actually lives on the reef itself and that previous studies using standard net sampling techniques have greatly underestimated plankton abundance over coral reefs.
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    Marine biology 41 (1977), S. 361-369 
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    Topics: Biology
    Notes: Abstract The bioenergetic basis of the biannual reproductive cycle of the solitary tunicate Styela plicata was investigated in order to evaluate hypotheses concerning the lack of larval settlement in summer. The rate of ingestion and absorption efficiency were measured in order to provide an estimate of the rate at which material was made available for maintenance, growth, and reproduction. At a given temperature the rate of ingestion was proportional to the 0.7 power of wet mass. the ingestion rate increased rapidly with increasing temperature between 12° and 18°C (Q10≃3), but was independent of temperature between 18° and 28°C. Absorption efficiency was independent of temperature and body size and averaged approximately one-third for both carbon and nitrogen. Metabolic maintenance costs were estimated from measurements of oxygen consumption and excretion of ammonia and urea reported for s. plicata. These require only 18±11% of the carbon and 37±22% of the nitrogen absorbed from the gut of S. plicata over the temperature range 12° to 28°C. Metabolic maintenance makes no excessive demands on the material absorbed in the gut at a particular time of year, and a surplus of carbon and nitrogen substrate is available throughout the year for growth and reproduction. Predation on larvae and young adults may be responsible for the low rate of settlement observed in summer months.
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    Marine biology 42 (1977), S. 9-15 
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    Topics: Biology
    Notes: Abstract Thallus segments of Fucus serratus L. and F. vesiculosus L. (Phaeophyceae, Fucales) were transferred into seawater media with a salinity range from 32.65 to 2.25‰ and maintained for at least 2 weeks. Several parameters of chemical composition as well as rates of photosynthetic and respiratory oxygen exchange, 14C-assimilate patterns, and release of 14C-assimilates into the culture medium have been investigated. Compared to controls, in both species dry weight, ash, chloride, and mannitol contents distinctly decline proportionally to reduction of salinity in the incubation media, whereas content of total N (in terms of protein content) remarkably increase. Respiratory O2-consumption is markedly increased at lower salinities, whereas rate of photosynthetic O2-evolution shows some depression. Relatively little effects of salinity changes are observed in distribution of photosynthetically assimilated 14C among the major groups of photosynthates. Release of 14C-assimilates into the incubation medium never exceeds 2% of total 14C-uptake, but is stimulated in media of reduced salt content. The results are discussed with emphasis on phenomena of long-term adaptation and osmoregulation in the marine fucoid species.
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  • 83
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    Marine biology 42 (1977), S. 69-84 
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    Topics: Biology
    Notes: Abstract Grazing by adult female Eurytemora affinis, Acartia tonsa and A. clausi on natural distributions of particles from the Chesapeake Bay has been investigated. During the course of a year's sampling, a wide variety of particle size-biomass distributions were observed as seasonal shifts in detritus, and over 150 algal species occurred. These distributions were grouped into 5 basic types in the analyses of feeding. All three species demonstrated similar capabilities for feeding over a broad range of particle size with selection (higher filtering rates) on larger particles and on biomass peaks. Feeding on multiple-peak distributions resulted in strong selection or “tracking” of each biomass peak with reduced filtering rates between peaks. Evidence is presented which suggests that the copepods first feed on large particles and then successively switch to biomass peaks of the smaller size categories. Comparisons of the feeding behavior of Eurytemora affinis and the Acartia species showing that the Acartia species have greater capabilities for taking large particles may be associated with modifications of their mouth parts for raptorial feeding. The results suggest considerable flexibility in copepod feeding behavior which cannot be explained solely by the mechanism of a fixed sieve.
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  • 84
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    Marine biology 42 (1977), S. 55-67 
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    Topics: Biology
    Notes: Abstract The components of 4 major groups of microplankton were identified and their numerical abundance determined in net samples collected at depth intervals down to 600 m at a permanent station off the H. Steinitz Marine Biological Laboratory, Elat. The samples analyzed were collected once a fortnight over a period of 1 year beginning in June 1974. The groups studied were the Cyanophyta, Bacillariophyta and Pyrrhophyta of the phytoplankton and the Tintinnina of the microzooplankton. The pattern of vertical distribution of the phytoplankton as a whole showed a general decrease in cell numbers with increasing depth. The blue-green algae, consisting mainly of Trichodesmium sp. trichomes, were confined primarily to the upper 100 m. The diatoms were unevenly distributed, with one species, a minute centric diatom, Thalassiosira subtilis, associated with a massive bloom during March 1975 between 300 and 400 m. The peridinians, the group with the largest number of species, included forms which were evenly distributed throughout the whole water column and forms limited either to the upper or deeper water strata in accordance with their light intensity preferences. The mass occurrence of newly-emerged dinoflagellate cysts of Pyrophacus horologicum, a weakly-armoured dinoflagellate, in the 200 to 300 m depth interval during April 1975, suggests that reproductive processes in dinoflagellates may also be light-controlled. The tintinnids, like the phytoplankton groups, were most abundant in the upper 100 m with a gradual decrease in numbers of individuals, though not in species, in the deeper water strata. The overall yearly pattern of microplankton distribution indicates 3 peaks: late fall and early summer peaks consisting primarily of blue-green algae and one in early spring consisting of several species of diatoms and peridinians and of species of tintinnids which thrive in the same niches as the phytoplankton. Both phytoplankton and tintinnid production was lowest during the summer months.
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    Marine biology 42 (1977), S. 93-98 
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    Topics: Biology
    Notes: Abstract The rate of the primary production of the phytoplankton community in the Petalion Gulf, Aegean Sea, was studied from January 1970 to May 1971, at a station situated at approximately Latitude 37°54′N; Longitude 24°11′E. A variety of physical and chemical parameters such as chlorophyll, primary nutrients (N,P,Si), temperature, salinity, oxygen and light penetration were also studied simultaneously. The rate of the gross primary production varied from 40 to 200 mg C m-2 day-1, with a mean value of 90 mg C m-2 day-1. The annual gross primary production was calculated to be 33 g C m-2, which is the minimum known value in the Aegean and Mediterranean Seas. Maximum production was found at the depth of 20 m on the average, mainly due to high light intensities. Petalion Gulf supports a small photosynthetic biomass, as indicated by the low seasonal values of chlorophyll a (0.01 to 0.18 mg m-2), the highest values being found in the summer. The low production rate noted may have been due to the low nutrient concentrations found: N, 0.04 to 0.32 μg-at/1; P, 0.00 to 0.15 μg-at/1; Si, 0.45 to 2.25 μg-at/1. It is suggested that inorganic phosphorus and nitrogen may alternate in limiting primary production rates in these oligotrophic waters. The temperate waters of the Petalion Gulf are stratified in summer (15.5° to 24.7°C) and well-mixed in winter (12.9° to 15.0°C); they are oxygen-saturated throughout the year, and of high transparency, with 86 m depth for the euphotic zone on the average yearly. The Petalion Gulf is therefore characterized as a typical oligotrophic biome in the Aegean and Eastern Mediterranean Seas.
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    Marine biology 42 (1977), S. 99-107 
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    Topics: Biology
    Notes: Abstract The estuary Byfjord (Sweden) is characterized by high primary production, a well developed meiofauna compared to the macrofauna, high epifaunal biomass, a low number of herbivorous copepods and a small fish stock. A simplified energy flow model of the ecosystem of the fjord is given. The energy transfer is approximated to 15%. About one-fourth-300 (metric) tons of carbon — of the annual primary production is suggested to be directly consumed and to produce 5 tons of zooplankton carbon and 40 tons of epifaunal (mainly Mytilus edulis) carbon. About 500 tons of carbon from the detritus pool are probably utilized in animal production. This amount will produce 5 tons of zooplankton carbon, 6 tons of meiofaunal carbon, and 3 tons of carbon from the benthic macrofauna. Production of fish is estimated at 0.3 ton carbon per year. M. edulis seems to be the only food resource in the fjord worth harvesting by man.
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    Marine biology 42 (1977), S. 109-118 
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    Topics: Biology
    Notes: Abstract Phytoplankton production and associated variables were measured in Flax Pond, a 52 ha salt marsh on the north shore of Long Island, New York, from July 1972 to October 1973. Measurements made up to five times per day, once per week, yielded a mean annual net primary production, determined by the 14C technique, of 20.5 mg C/m3/h; daily means were as high as 60.0 mg C/m3/h. However, when productivity was calculated for the entire marsh ecosystem, the shallow water in the salt marsh produced only 11.7 g C/m2 of marsh/year. There was a net flux of phytoplankton from the coastal waters into the marsh; during the summer up to 0.2 g chlorophy 11/m2 of marsh was carried in with the tides daily and remained in the marsh. Analysis of the productivity data, as well as variables associated with productivity (pH, standing crop, nutrients, extinction coefficient), indicated that the aquatic portion of the marsh behaved more as a net consumer rather than a net producer of phytoplankton.
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    Marine biology 42 (1977), S. 119-129 
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    Topics: Biology
    Notes: Abstract Isotopic exchange occurs between coral skeleton and 45Ca++ and H14CO 3 - in seawater. Exchange of 14C onto skeletons is more rapid than exchange of 45Ca++. Exchange of 14C from skeletons to seawater takes place more slowly than exchange of 45Ca++ to seawater. When living coral is incubated in the dark with radioisotopes for 1 h, the tissues contain considerably more radioactivity than is associated with the skeleton. The tissue radioactivity reflects permeation of tissues and coelenteron by radioactive compounds from the incubation seawater. Addition of alkalis to cardioactive seawater results in a radioactive precipitate, part of which becomes associated with any coral skeleton present, and part of which forms on the wall of the containing vessel. Strong alkali removes biologically-deposited radioisotope from coral skeletons. Deposition, of 14C from H14CO 3 - in skeletons of living coral incubated in the dark is greater than in dead coral. The reverse situation occurs with 45Ca++.
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    Marine biology 42 (1977), S. 131-141 
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    Topics: Biology
    Notes: Abstract A comparison of two different methods was made using the tracer technique. The first test was performed by adding only one defined amont of a 14C-labelled compound to the sample, the second one by adding different amounts of the same labelled compound, followed by a kinetic approach. In a coastal area of the western Baltic Sea (Kiel Fjord) the turnover times of various compounds (glucose, glucosamine, aspartic acid, leucine, lysine and acetate) were determined. In the open Baltic Sea (especially the Bornholm-Basin) the study was confined to glucose. The variations between the results of the two methods for determining the turnover times are only small for samples from eutrophic or polluted regions. However, larger discrepancies exist with samples from oligotrophic areas. Here, turnover times obtained with the first method were consistently shorter (sometimes only half as long) than, those obtained with the second method. This difference is attributed to the fact that in areas of low bacterial activity e.g. in oligotrophic water bodies, organic-substance uptake by the entire natural population of heterotrophic micro-organisms does not follow exactly the Michaelis-Menten equation. This is likely to be due to a greater population heterogeneity resulting in an increased diversity of uptake characteristics. However, since the calculation of turnover time according to the second method is based on a modification of this equation, errors are introduced.
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  • 90
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    Notes: Abstract There is evidence in the scientific literature of differences in the genetic control of the enzyme phosphoglucose isomerase (PGI) in the European eel Anguilla anguilla and the American eel A. rostrata. Two PGI loci have been described in the former species, while 3 PGI loci have been reported in the latter. There is also evidence of differences in the tissue distribution of PGI isoenzymes in European eels from the English Channel and the Mediterranean Sea which suggest genetic diversity between the two populations. Studies carried out on two fairly large samples of Mediterranean (coast of Tuscany) and Atlantic (coast of Wales) A. anguilla, and on a small sample of A. rostrata, have permitted a clearer and more complete interpretation of the complex PGI electrophoretic patterns present in the tissues of eels. No difference, however, was observed in PGI genetic control between A. anguilla and A. rostrata: two loci encode PGI in both species. The patterns of tissue activity of PGI isoenzymes in the two samples of A. anguilla were essentially the same. There were, also, no significant differences in the PGI allele frequency between the two samples of European eels. These results, which support the genetic homogeneity of eels from different parts of Europe, are discussed in relation to the classical and more recent theories on the origin of the Atlantic and Mediterranean eels.
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    Marine biology 43 (1977), S. 265-276 
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    Topics: Biology
    Notes: Abstract Adults of the softshell clam Mya arenaria were continuously subjected to a flowing raw seawater solution containing a mixture of salts of manganese, zinc, lead, nickel, copper, and cadmium. Final calculated concentrations, in μg l-1, of the toxicant solution were 7200 Mn, 2500 Zn, 70 Pb, 50 Ni, 50 Cu and 1 Cd; these concentrations approximated highest measured levels within surficial interstitial sediment waters from mid-Narragansett Bay, Rhode Island. M. arenaria were also subjected to a 20% solution, i.e., 1440 Mn, 500 Zn, 14 Pb, 10 Ni, 10 Cu, and 0.2 μg l-1 Cd. One study was conducted for 112 days in winter at 0° to 10°C and another for 16 days in summer at 16° to 22°C. In the winter study, all clams exposed to a 100% solution died between the 4th and 10th week; soft parts of survivors at 6 weeks contained about 19 times more Pb, 15 x more Zn, 12 x more Cu, 10 x more Mn, 3 x more Ni and 0.1 x more Cd than controls; relatively minor changes in whole body elemental content of Ca, Cr, Fe, K, Mg, Na, Sr, and V were observed. Clams exposed to a 20% solution during winter survived the 112 day study; at that time these contained about 5 x more Cu, 4 x more Mn, 3 x more Zn and about 2 x more Pb than controls; comparatively minor changes were observed in other elements examined. In the summer study, all M. arenaria subjected to the 100% solution died between 6 and 14 days; survivors from this group at 7 days contained about 25 x more Pb, 13 x more Cu, 11 x more Zn, 7 x more Mn, and 3 x more Ni than controls; other changes in elemental content were not as pronounced. Mortality in the 20% group during summer was slightly higher than controls during the 16 day study; at 14 days survivors from this group contained about 12 x more Mn, 7 x more Pb, 7 x more Zn, 4 x more Cu, and 3 x more Ni than controls. Survival and bioaccumulation patterns were not altered through feeding a supplemental diet of algae. The significance of these findings are discussed in terms of potential environmental perturbations, especially local dredging practices.
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    Marine biology 43 (1977), S. 343-359 
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    Topics: Biology
    Notes: Abstract The sandy-bottom macrobenthic community of Mugu Lagoon, a relatively pristine southern California (USA) marine lagoon, demonstrated (1) nearly constant community composition over 37 months of observation, (2) relatively little temporal variability in the population densities of the most abundant species over 37 months, and (3) a pattern of depth stratification in which very little vertical overlap existed among the six most abundant species. The only two species whose vertical distributions overlapped broadly showed horizontal spatial segregation, each abundant in different areas within the sand habitat. These community characteristics imply the importance of biological factors in structuring the sand benthos. The relatively large volume required for living space by these macrofauna suggests that competition for space may be the biological factor most important in determining the observed temporal and spatial abundance patterns. The muddy-sand community and the mud community of Mugu Lagoon also revealed similar patterns of stratification: new abundant species replaced species at the same sedimentary level while not greatly affecting species populations at other non-overlapping levels. In the sand community of Tijuana Slough, two of the abundant species of Mugu Lagoon's sand community were nearly absent as an apparent result of human over-exploitation. Probably in response, densities of species living at the sedimentary levels normally occupied by the missing species were much higher than would be predicted if competition for space were unimportant. In field experiments, removal of the deposit feeder Callianassa californiensis resulted in high recruitment of Sanguinolaria nuttallii, whereas control areas showed no S. nuttallii recruitment. Experiments also suggest that negative intraspecific interactions between Cryptomya californica individuals may explain the observed rapid emigration from areas of artificially high density. Perhaps the relatively great environmental predictability of southern California lagoons has permitted competitive interactions to play a singnificant role in determining the temporal and spatial abundance patterns of the soft-bottom macrobenthos.
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    Marine biology 44 (1977), S. 287-292 
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    Topics: Biology
    Notes: Abstract The maintenance of a uniform diet for Carcinus maenas (L.), where this crab is used as test animal in the laboratory, precludes the use of fresh food, e. g. mussels, for many reasons; not the least of these is the seasonal variation in the nutritive value of such food. Different types of fresh food are variably accepted by C. maenas, dependent on such factors as taste and the consistency of the food. The crabs will eat freeze-dried food set in agar-agar. A diet of this food is, however, inferior to one of fresh food as its preparation destroys essential substances and storage causes aging. In order to eliminate these disadvantages, a better quality artificial diet was developed, one which nevertheless does not attain the quality of fresh food. This diet can be further improved by varying the proportions of the individual constitutents.
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  • 94
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    Notes: Abstract Populations of Fundulus heteroclitus (L.) at the beginning of a growth season in a New England salt marsh consist of 3 yearly age classes, with the 1-year-old class contributing most of the biomass. Calculation of production rates revealed that the young fish were the most active part of the population and that females were more productive than males. The entire population spent equal amounts of energy in growth and in metabolism. Including the young of the year, we obtained total production of 160 kg dry weight/ha, a value among the highest obtained for natural fish populations. About 5 to 15% of the production is available to predators. Rates of food consumption by F. heteroclitus are high enough to turn over the population of prey relatively often. Popululations of F. heteroclitus are thus capable of exerting an important influence on the abundance and distribution of their prey.
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    Marine biology 40 (1977), S. 165-171 
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    Topics: Biology
    Notes: Abstract Tolerance limits to acute temperature, and temperature and low dissolved oxygen stresses were determined for 5 zoeal stages and megalops of Cancer irroratus Say. The acute temperature limits for a 120 min exposure were all approximately 29.0°C, with little interstage, variation, while those for 240 min exposure ranged from 27.3° to 28.5°C. More interstage variation was shown when temperature and low dissolved oxygen stress were combined, with low oxygen tolerance decreasing as temperature increased. The first, second, and fourth zoeal stages display similar patterns of response. The third and fifth stages show a similar response, but are different from the former stages. The megalops is relatively insensitive to changes in oxygen concentration with temperature. The larval stages did not show a progressive increase in tolerance to temperature or low dissolved oxygen with development. Tolerance to these factors may be related to size, stage of development and activity level. The larval stages have capacities to tolerate a wider range of these factors than they require in the natural environment.
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    Marine biology 40 (1977), S. 195-195 
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  • 97
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    Notes: Abstract Observations have been made on seasonal fluctuations in dissolved inorganic nutrients, internal reserves of nitrogen and growth rates in Laminaria longicruris. The onset of winter growth in shallow-water stations (6 and 9 m) correlated well with improved dissolved nitrate conditions in the sea. During the winter, reserves of NO 3 - were accumulated by the plants and reached maximum values of 150 μmoles per g fresh weight in March. This represents a concentration factor of approximately 28,000 over the ambient levels, or an internal nitrogen reserve of 2.1% of the dry weight of the tissue. Depletion of this nitrogen pool followed the disappearance of the external NO 3 - with a lag period of up to 2 months. Rapid kelp growth was measured during this period. Reserves of organic nitrogen also reached maximum values in March and declined slowly throughout the summer into autumn. It is suggested that the combined inorganic and organic nitrogen reserves sustain the rapid growth rates into July and at reduced rate through the late summer. Fertilization of an experimental perimental kelp bed with NaNO3 increased the internal plant reserves of NO 3 - and produced a much improved summer growth rate. The enriched plants developed very small reserves of carbohydrate during the rapid summer growth phase.
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    Marine biology 40 (1977), S. 217-224 
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    Topics: Biology
    Notes: Abstract The growth and spawning of Lacuna pallidula and L. vincta were measured in the laboratory over 7 months. In both cases, there were significant differences between the mean number of eggs per batch or weight of egg batches from females of the same species and also between rates of spawning by females of the same species. The reproductive effort of L. vincta, estimated by the ratio total spawn weight: body weight and by the time taken to exceed body weight in cumulative spawn, is approximately twice that of L. pallidula. L. vincta has a long-lived planktotrophic larva, while L. pallidula has direct, lecithotrophic development, and therefore in this instance planktotrophic development seems to be more expensive to the parent than lecithotrophic development. Published work on two Pacific seastars leads to the opposite conclusion, and it is suggested that the paradox can be resolved in terms of r-K-selection theory. In both cases, the r-selected species has a higher reproductive effort, notwithstanding that the snail is planktotrophic and the seastar lecithotrophic in development.
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  • 99
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    Notes: Abstract The embryonic and larval stages of the quahog clam Mercenaria sp. were exposed to the water-soluble fractions (WSFs) of 6 oils and the effects on survival and growth rate of the various stages were noted. Kuwait crude oil was the least toxic on initial exposure to both stages, having LC50 values in excess of 10 ppm after continuous exposure to the WSF for up to 6 days. However, at 10 days, Kuwait was slightly more toxic than southern Louisiana crude oil, with both oils having LC50 values near 2 ppm. Florida Jay crude oil was much more toxic, with an LC50 of less than 1 ppm at 48 h and less than 0.2 ppm at 10 days. Two refined oils, No. 2 fuel oil and Bunker “C”, had LC50 values of 1 to 2 ppm after 48 h, while used crankcase motor oil, the most toxic oil tested, had LC50 values of 0.10 ppm or less at all exposure times. Larvae surviving exposure to water-soluble fractions of the various oils often grew at slower rates than the controls.
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    Marine biology 40 (1977), S. 303-308 
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    Topics: Biology
    Notes: Abstract Temperature, salinity, bottom-sediment type, and zinc concentration all influenced Cd uptake by 4 marine bivalves (Mya arenaria, Mytilus edulis, Mulinia lateralis and Nucula proxima) in short-term static assay systems using 109Cd as a tracer. The experimental system consisted of aquaria containing 20 l of seawater maintained under controlled light and temperature conditions. The water contained either 5 or 20 μg/l Cd and tracer. Distribution and kinetics of the metal were monitored in the water column and organisms. The results demonstrate that Cd uptake rates differed widely among the organisms tested. An increase in temperature increased Cd uptake rate by all test organisms. A decrease in salinity increased Cd uptake by all organisms tested. The presence of bottom sediment depresses Cd accumulation in some benthic animals. Zinc in concentrations of 0.5 mg/l substantially decreased Cd uptake by Mytilus edulis and Mulinia lateralis. It is suggested that all important species and environmental variables be considered when studying heavy-metal uptake by marine organisms or when establishing water-quality criteria.
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