ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • 1
    Electronic Resource
    Electronic Resource
    Lethal and sub-lethal effects of phototrophic endoliths attacking the shell of the intertidal mussel Perna perna (1999)
    Springer
    Marine biology 135 (1999), S. 497-503 
    Details
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Animals that bore into calcareous material can cause considerable damage to molluscan shells. In contrast, smaller microbial phototrophic endoliths have until recently been thought of as relatively benign. Phototrophic endoliths (primarily cyanobacteria) infest the shells of 50 to 80% of midshore populations of the mussel Perna perna (L.) in South Africa. This infestation causes clearly visible shell degradation, and we record here ecologically important lethal and sub-lethal effects (e.g. changes in growth and reproductive output) of the endoliths on their mussel hosts. Endolith infestation reduced the strength of shells significantly and also affected shell growth. In situ marking of shells, using the fluorochrome calcein, showed that infested and non-infested mussels increased in shell length at the same rate. However, the rate of increase in shell thickness (associated with shell repair) was significantly faster in infested than in uninfested individuals. This increase in the rate of shell thickening was not sufficient to compensate for rapid endolith-induced shell degradation and, around the site of adductor muscle attachment, infested shells were thinner than their uninfested counterparts. The shells of 18% of recently dead mussels had holes induced by endolith erosion. This effect was highly size dependent, and the proportion of mortality due to endoliths rose to almost 50% for the largest mussels. The re-routing of energy due to shell repair had important sub-lethal effects on the reproductive rates of mussels. During the reproductive period, mean dried flesh mass for large (〉70 mm), non-infested P. perna was substantially higher than for infested individuals. This difference was almost entirely due to differences in gonad mass, which was approximately 100% higher for non-infested mussels. We conclude that, by attacking the shell, phototrophic endoliths reduce both the longevity and reproductive output of large mussels on the midshore.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002270050650
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Incidence and distribution of phototrophic shell-degrading endoliths of the brown mussel Perna perna (1999)
    Springer
    Marine biology 135 (1999), S. 505-514 
    Details
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The incidence, distribution and infestation sequences of four endolithic cyanobacteria in the shells of the brown mussel Perna perna (L.) were studied along the south coast of South Africa. The incidence of endolith-infested shells varied significantly among the 21 study sites (∼23 to 95%), with highest infestation rates occurring on promontories and headlands as compared to sites within bays. At a smaller scale, the incidence of infested shells also varied with tidal height, being high at the upper tidal levels of mussel distribution and low or absent on the lowshore. The observation that small-scale variability in infestation rates was positively related to water movement suggested that physical damage to the outer protective periostracum of mussels may have facilitated colonisation by endoliths. This hypothesis was supported by the fact that shells with artificially damaged periostraca became infested at a greater rate than did control shells. Once colonisation by the filamentous cyanobacteria Plectonema terebrans, Hyella caespitosa and Mastigocoleus testarum had taken place, endoliths spread throughout the shell, causing progressive shell deformation and damage. Only older shells that were infested by the late successional, cavity-forming Pleurocapsa sp., however, exhibited severe shell deformations, became brittle and eventually fractured near the structurally important site of adductor muscle attachment. Heterotrophic endoliths typically associated with shell degradation in previous studies were extremely rare and if present did not contribute to shell disintegration. Although it is generally perceived that endolithic algae and cyanobacteria are restricted to the surface layers of shells by light limitation within the substratum, it is clear from this study that the interaction of a combination of factors (i.e. erosion of the periostracum, successional sequence of colonists and mechanical properties of the shell) may result in phototrophic endoliths causing severe shell degradation and eventually mussel mortality.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002270050651
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Use of the fluorochrome calcein as an in situ growth marker in the brown mussel Perna perna (1999)
    Springer
    Marine biology 133 (1999), S. 455-460 
    Details
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract This study assesses the potential of the fluorochrome calcein for use as a growth marker in bivalve shell growth studies. Calcein solutions were administered in situ to the brown mussel Perna perna (Linneaus), both by injection and immersion, and the effect of calcein concentrations on fluorescent mark deposition and mussel mortality was investigated in the laboratory. Field investigations showed that, 1 month after administration, calcein injection (125 mg l−l) into the mantle cavity produced superior results to the immersion treatments (150 and 500 mg l−l). Both methods resulted in fluorescent mark incorporation at the growing edge, but during immersion general calcein deposition associated with endolith activity resulted in fluorescence that made identification of a distinct datum point difficult. In contrast, the injection method produced clearly defined growth marks, which were easily distinguished from autofluorescence and persisted without visible degradation for a minimum of 9 months. Shell growth rates estimated using the fluorescent mark as a datum point were similar to those from earlier studies using different methods. Laboratory investigations revealed that at␣calcein concentrations of 80 mg l−l and above, 100% of juvenile (20 to 30 mm) and adult mussels (60 to 70 mm) retained a visible growth mark, while at concentrations 〉160 mg l−l all marks were bright and clearly defined. No mussel mortality was exhibited at any time, even at calcein concentrations of 640 mg l−l, eight times higher than those required for mark deposition. These results suggest that, compared to traditional methods of bivalve growth determination, the use of fluorochromes presents a relatively inexpensive, non-invasive and rapid alternative. When using calcein as a growth marker, problems associated with some other fluorochromes (e.g. inconsistent mark incorporation, high post-treatment mortality) were not exhibited.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002270050485
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Distribution of algae on tropical rocky shores: spatial and temporal patterns of non-coralline encrusting algae in Hong Kong (1996)
    Springer
    Marine biology 125 (1996), S. 177-187 
    Details
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Encrusting algae have been described as dominant space occupying species on rocky shores around the world. Despite their abundance, however, most studies classify species under generic names (e.g. Ralfsia sp.) or as a functional group (e.g. encrusting algae), thereby underestimating the number of species present and their ecological importance. Studies on six rocky shores of varying exposure, in Hong Kong, recorded eight common species of encrusting algae. The greatest abundance of encrusting algae was recorded on shores of intermediate exposure, where four distinct zonation bands could be identified; a cyanobacterial “Kyrtuthrix-Zone” in the upper midlittoral, a “Bare-Zone” below this, a “Mixed-Zone” in the lower midlittoral and a “Coralline-Zone” in the infralittoral fringe. Abundance declined on shores of greater and lower exposure to wave action, where bivalves and barnacles were competitively dominant. Certain species were found in greater abundance on exposed shores (e.g. Dermocarpa sp. and Hildenbrandia occidentalis), while others preferred more sheltered shores (e.g. Hildenbrandia prototypus and Kyrtuthrix maculans). With the exception of some cyanobacterial crusts, the abundance of encrusting algae was always greatest towards the low shore, an area of decreased physical stress and increased herbivore density. Zonation patterns showed seasonal variation associated with the monsoonal climate of Hong Kong. Most species increased in abundance during the cool season, while during the summer months the cover and vertical extent of encrusting algae decreased in relation to summer temperatures, although K. maculans increased in abundance during the summer. On Hong Kong shores, encrusting algae have a high species richness and exhibit within-functional group spatial and temporal variation which is mediated by herbivory and seasonal, physical stresses.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00350772
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    THE USE OF SEISMIC SHEAR WAVES AND COMPRESSIONAL WAVES FOR LITHOLOGICAL PROBLEMS OF SHALLOW SEDIMENTS (1984)
    Oxford, UK : Blackwell Publishing Ltd
    Geophysical prospecting 32 (1984), S. 0 
    Details
    ISSN: 1365-2478
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Geosciences , Physics
    Notes: From a great variety of in situ shear wave experiments, i.e., reflection, refraction and borehole surveys in the shallow sediments of the north German plains, several specific properties have been derived. Shear waves (S) differ from compressional waves (P) in that:〈list xml:id="l1" style="custom"〉1they are not affected by the degree of water saturation. Thus, they provide a better correlation between the velocity Vs and (solid) lithology;2they generally have lower frequencies, but shorter wavelength and, hence, a better resolution of thin layers;3they have lower absorption Qs−1 and hence a better penetration in partially saturated and gas-containing sediments than P-waves.Correlations have been established between Vs and the confining pressure and between reduced Vs values and several lithological parameters like the grain size of sandy material. More lithological and hydrological information is obtained by using S- and P-wave surveys along the same profile. The best information on a sedimentological structure is obtained by the simultaneous observation of Vs, Vp, Qs and Qp.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2478.1984.tb01712.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    RADIATION AND RECEIVER PATTERN OF SHEAR AND COMPRESSIONAL WAVES AS A FUNCTION OF POISSON'S RATIO (1983)
    Oxford, UK : Blackwell Publishing Ltd
    Geophysical prospecting 31 (1983), S. 0 
    Details
    ISSN: 1365-2478
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Geosciences , Physics
    Notes: Shear (= S) wave studies in addition to compressional (= P) wave surveys have revealed that S-wave velocities are much more variable than P-wave velocities. This strongly affects Poisson's ratio σ, especially in young sediments. It is shown that σ has a great influence on the directivity pattern, i.e., on the radiation and receiving characteristic of horizontal sources and receivers. For their calculation, well-known surface boundary conditions and White's statement of the reciprocity relation (White 1965) are used. They also form the basis for the combination of source and receiver patterns essential for practical field work. The various combinations of horizontally and vertically arranged sources and receivers are investigated with regard to their directivity pattern, their amplitude ratio and, in general, to their usefulness in seismic prospecting.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2478.1983.tb01061.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    facet.materialart.
    Unknown
    Incidence and distribution of phototrophic shell-degrading endoliths of the brown mussel Perna perna (1999)
    Springer
    Details
    Publication Date: 1999-12-04
    Print ISSN: 0025-3162
    Electronic ISSN: 1432-1793
    Topics: Biology
    Published by Springer
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 8
    facet.materialart.
    Unknown
    Spatial and temporal shifts in stable isotope values of the bottom-dwelling shrimp Nauticaris marionis at the sub-Antarctic archipelago (2004)
    Springer
    Details
    Publication Date: 2004-02-01
    Print ISSN: 0025-3162
    Electronic ISSN: 1432-1793
    Topics: Biology
    Published by Springer
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 9
    facet.materialart.
    Unknown
    Intra-annual variation in the foraging ecology of the endangered endemic Barau’s Petrel (Pterodroma baraui) from Réunion Island, south-western Indian Ocean: insights from a multifaceted approach (2016)
    Springer
    Details
    Publication Date: 2016-01-01
    Print ISSN: 0025-3162
    Electronic ISSN: 1432-1793
    Topics: Biology
    Published by Springer
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 10
    facet.materialart.
    Unknown
    Zooplankton community structure in the kelp beds of the sub-Antarctic Prince Edward Archipelago: are they a refuge for larval stages? (2002)
    Springer
    Details
    Publication Date: 2002-10-01
    Print ISSN: 0722-4060
    Electronic ISSN: 1432-2056
    Topics: Biology
    Published by Springer
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...