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  • 1
    Electronic Resource
    Electronic Resource
    Sediment characteristics and colonization of soft-bottom benthos: a field manipulation experiment (1997)
    Springer
    Marine biology 128 (1997), S. 475-487 
    Details
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A field manipulation experiment was carried out to test the effects of sediment characteristics (particle size and organic content) on colonization of soft-bottom benthos. Defaunated mud and sand in experimental trays were exposed at sub-tidal levels of two sites with sandy and muddy sea bottom, and retrieved monthly for examination of benthic composition. Seventy-eight out of the 107 species recorded, and 50% of the dominant species identified in the present study, were common in both the sand and mud trays. Classification analysis revealed higher faunal similarity of benthic composition in both sediment types within each of the two study sites. Results of three-way ANOVA (Sediment, Site and Time) showed that sediment effect was only significant for colonization of bivalves and gastropods, but not for polychaetes, amphipods, total species and individual numbers, or overall benthic diversity and evenness. This suggested that many of the benthic species can colonize both sediment types, and that factors other than sediment particle size and organic content may play a significant role in determining colonization of these species. The faunal composition of the same sediment type between sites was found to be different, indicating that the availability and abundance of benthic larvae/adults may be more important than sediment characteristics in determining benthic settlement. An increase in faunal similarity between mud and sand was observed over the study period, implying that the importance of sediment characteristics to benthic colonization decreased with exposure time.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002270050114
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  • 2
    Electronic Resource
    Electronic Resource
    An energy budget for individual barnacles (Balanus glandula) (1978)
    Springer
    Marine biology 45 (1978), S. 225-235 
    Details
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract An annual energy budget was constructed for individual adult barnacles (Balanus glandula Darwin) for the first year after settlement. The production of body tissue, egg, shell, aquatic and aerial respiration, molting and faecal production was determined and consumption was derived from the summation of these budget items. To provide an estimation of the accuracy of the budget equation, energy budgets were constructed for three small groups of barnacles (n=40) kept under laboratory conditions, in which the budget items, including consumption, were determined independently. The results of the laboratory energy budgets indicated that consumption values derived from the summation methods for the three groups of barnacles were 7.4% higher and 16.2 and 15.6% lower than those determined by actual feeding experiments. The average consumption, assimilation and production of individual barnacles were estimated to be 699.5, 647.3 and 159.6 cal year−1, respectively. B. glandula has an exceptionally high assimilation efficiency (92.5% from the annual budget and 99.3% from the laboratory budgets) but a low gross production efficiency (22.8%) and net production efficiency (24.7%). A very large proportion of energy (67.4%) was lost in respiration. The second most important budget item was egg production (12.3%); followed in decreasing order by: shell production (6.6%)〉 production of body tissue (3.9%)〉molting (2.3%).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00390605
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  • 3
    Electronic Resource
    Electronic Resource
    Energy flow and population dynamics of the barnacle Balanus glandula (1979)
    Springer
    Marine biology 54 (1979), S. 83-89 
    Details
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The energetics and population dynamics of a barnacle (Balanus glandula Darwin) population in British Columbia, Canada, were studied. Consumption, energy flow, production and mortality were 6844.6, 6667.0, 2896.5 and 2522.8 Kcal m-2 year-1, respectively. These energy flow and production values are among the highest for animal populations reported, and therefore strongly suggest the functional importance of E. glandula in littoral systems. The young age groups of the first-year settlements were most important in contributing to the energy flow, production and reproduction of the entire population. Most of the assimilated energy in the older age groups was used in respiration.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00387054
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  • 4
    Electronic Resource
    Electronic Resource
    Variations in benthic community structure in a sub-tropical estuary (1981)
    Springer
    Marine biology 64 (1981), S. 191-198 
    Details
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A one year study was carried out to investigate the variations in benthic community structure along an environmental gradient of salinity and bottom substratum in a sub-tropical estuary in Hong Kong. The community was dominated by the gastropod Turritella terebra, and to a lesser extent, by the gastropod Murex trapa and the crab Portunus hastatoides. The total number of animals, biomass as well as the domanance of T. terebra in the community decreased, while species diversity increased along a gradient of increasing salinity and decreasing siltclay fraction of the sediment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00397108
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  • 5
    Electronic Resource
    Electronic Resource
    An experimental study on recolonization and succession of marine macrobenthos in defaunated sediment (2000)
    Springer
    Marine biology 136 (2000), S. 291-302 
    Details
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Hypoxia/anoxia in coastal waters is a world wide problem which often results in mass mortality and defaunation of benthos. In this study, field experiments were carried out to examine recolonization and succession of macrobenthic infauna in defaunated sediments, and the time required for recovery from complete defaunation to a stable community. Trays (33 cm length × 25.5 cm width × 11 cm depth) of defaunated sediment were exposed at the subtidal of a pristine site in subtropical Hong Kong. Temporal changes of macrobenthic communities in defaunated sediment were analyzed by univariate and multivariate statistics, and compared with those in undisturbed natural sediment at the same site. Initial colonization of macrobenthos occurred rapidly. A total of 42 species was found, with an average of 258 animals per tray and 24 species per tray recorded in the first month. Abundance showed a small peak (496 animals per tray) after 3 months, reached a sharp peak (1154 animals per tray) after 6 months, and declined thereafter. Species number increased gradually, reached a maximum (68 species per tray) after 9 months, and then decreased. Recolonization was predominantly contributed by larval settlement rather than adult migration. Temporal changes in abundance, species number and diversity of the macrobenthic community in defaunated sediment resemble the spatial changes along a decreasing pollution gradient previously defined by other authors. Results of this experiment suggest that newly available sediment may allow more species to colonize (or coexist) than sediment pre-occupied by an established community. This is probably due to less interspecific competition in the former habitat. No significant difference in abundance or species richness was observed between defaunated and natural sediments after 15 months, suggesting that a stable community had been achieved, although minor variations in species composition were still discernible between defaunated and natural sediments.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002270050687
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  • 6
    Electronic Resource
    Electronic Resource
    Metabolic adjustments in the common carp during prolonged hypoxia (2000)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of fish biology 57 (2000), S. 0 
    Details
    ISSN: 1095-8649
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Biochemical and respiratory changes in the common carp Cyprinus carpio, were studied 6, 24, 96 and 168 h upon exposure to hypoxia (0·5 mgO2 l−1). Modification of kinetic properties of phosphofructokinase (PFK-1), coupled with a decreased in PFK-1 activities, were evident in muscle. No changes in kinetics and activities could be observed in muscle pyruvate kinase (PK) and lactate dehydrogenase (LDH). A decrease in muscle citrate synthase (CS) and an increase in muscle cytochrome c oxidase (CCO) were found. The common carp was able to maintain a constant level of muscle glycogen, muscle ATP, and liver CS throughout the 168-h experimental period. Changes in activities of liver LDH and muscle CCO were observed only at 168 h, which indicates that common carp may switch to alternative metabolic pathway to deal with prolonged hypoxia. A severe decrease in liver glycogen was accompanied by increases in lactate levels in both the muscle and liver. Oxygen consumption rate was reduced under hypoxia, but resumed to normoxic levels within 2 h upon return to normoxic condition. Overall, these results indicate that carp adopt different strategies in an attempt to deal with short term and long term hypoxia in the natural environment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1095-8649.2000.tb00478.x
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  • 7
    Electronic Resource
    Electronic Resource
    Interacting effects of water temperature and dietary protein levels on post-prandial ammonia excretion by the areolated grouper Epinephelus areolatus (Forskål) (1999)
    Oxford, UK : Blackwell Science Ltd
    Aquaculture research 30 (1999), S. 0 
    Details
    ISSN: 1365-2109
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-2109.1999.00391.x
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  • 8
    Electronic Resource
    Electronic Resource
    Effects of Cadmium and Phenol on Motility and Ultrastructure of Sea Urchin and Mussel Spermatozoa (2000)
    Springer
    Archives of environmental contamination and toxicology 38 (2000), S. 455-463 
    Details
    ISSN: 1432-0703
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Medicine
    Notes: Abstract. Computer-assisted sperm analysis (CASA) was used to study the effects of Cd(II) and phenol on sperm motility of sea urchin and mussel. In parallel, ultrastructural changes of sperm induced by these two toxicants were also investigated and related to motility impairment. Spermatozoa of sea urchin were more sensitive than mussel spermatozoa to both toxicants. Sea urchin sperm motility showed a good dose-response relationship to Cd(II) levels as well as exposure time. Exposure to the two toxicants changed the size and shape of the midpiece, which might affect the balance of spermatozoa in their swimming. The plasma membrane became more convoluted, and such a change might affect the streamlining and integrity of spermatozoa and hinder their normal movement patterns. Most important, disorganization of mitochondrial membranes and cristae was observed, suggesting disruption of ATP supply for sperm movement. Cadmium also induced greater ultrastructural damages in sea urchin spermatozoa.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002449910060
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  • 9
    Electronic Resource
    Electronic Resource
    Spermatogenesis of the green-lipped mussel Perna viridis with dual patterns of acrosome and tail development in spermatids (1999)
    Springer
    Helgoland marine research 53 (1999), S. 62-69 
    Details
    ISSN: 1438-3888
    Keywords: Key words Spermatogenesis ; Perna viridis ; Acrosome formation ; Flagellum development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Spermatogenesis in the mussel Perna viridis was studied by electron microscopy. Results demonstrated that cytological development in spermatogonia and spermatocytes was similar to that previously described in other Mytilidae. Acrosome formation began with the arising of proacrosomal vesicles in spermatogonia. The abundance of proacrosomal vesicles increased in spermatocytes, which were flagellated. However, during spermiogenesis, dual patterns of acrosome development as well as flagellum development could be found among spermatids in a male gonad. The two lines of acrosome formation in spermatids ultimately gave rise to morphologically similar acrosomes. The two lines of flagellum development in spermatids resulted in the formation of sperm cells with either a typically posteriorly directed tail or an anteriorly directed tail.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/PL00012139
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  • 10
    Electronic Resource
    Electronic Resource
    Food segregation in three species of portunid crabs (1997)
    Springer
    Hydrobiologia 362 (1997), S. 107-113 
    Details
    ISSN: 1573-5117
    Keywords: diet ; food segregation ; inter-specific competition ; portunidcrabs
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Gastric mills of 2,619 specimens of portunid crabs(Portunus pelagicus, P. sanguinolentus andCharybdis feriatus) in Tolo Harbour, Hong Kongwere examined. Of these, 1,498 containedrecognizable food items. A total of 34 food items wereidentified, 10 of which (29.4%) were common to thethree crab species. The principal food items werebivalves, decapods, fish and algae. However, thepercent frequency of occurrence of these food itemsdiffered significantly (ANOVA, p 〈 0.001) among thecrabs. In addition to these principalfood items, differences were noted in other dietarycategories: P. pelagicusand P. sanguinolentus fed on the brittle starOphiura kinbergi, whereas P.sanguinolentus and C. feriatus fed on detritusand gastropods. The diet of P. sanguinolentuswas found to be more similar to C. feriatus thanto P. pelagicus. Exploitation of different fooditems and selective feeding on common prey may reduceinter-specific competition for natural food resourcesand allow the three portunid crabs to co-exist in thesame habitat.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1003126415990
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