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Full-Text Articles in Life Sciences
Natural And Disturbance-Induced Demographic Variation In An Infaunal Polychaete, Nephtys Incisa, Roman Zajac, Robert B. Whitlatch
Natural And Disturbance-Induced Demographic Variation In An Infaunal Polychaete, Nephtys Incisa, Roman Zajac, Robert B. Whitlatch
Biology and Environmental Science Faculty Publications
Demography of the infaunal polychaete Nephtys incisa was investigated for periods of 1 yr prior to and following disturbance (dredge material disposal) at a site in central Long Island Sound, USA. Infaunal grab samples were taken at 5 stations 200 m to 3 km apart. The demography of populations at each station was based on age-classes spanning juveniles to adults 4 + yr of age. Age-specific survivorship and fecundity were based on changes in mean density of each cohort and a positive correlation between female size and egg production, respectively. Analyses of population matrix models indicated pre-disposal populations had positive …
Effects Of Inter-Specific Density And Food Supply On Survivorship And Growth Of Newly Settled Benthos, Roman Zajac, Robert B. Whitlatch, Richard W. Osman
Effects Of Inter-Specific Density And Food Supply On Survivorship And Growth Of Newly Settled Benthos, Roman Zajac, Robert B. Whitlatch, Richard W. Osman
Biology and Environmental Science Faculty Publications
Using a laboratory model system comprised of newly settled oysters Crassostrea virginica and established fouling species (Botrylloides sp. initially, and others including Styela clava and Ciona intestinalis as the experiment progressed), we tested how differences in food supply and competitor density may affect post-settlement surivorship and growth of sessile marine invertebrates over a 44 d period. After 15 d, results were mixed but indicated that both food and density conditions affected growth and survivorship significantly, with some suggestion of high food levels ameliorating high density effects However, 44 d after settlement, oysters had reduced survivorship and growth when competitors …
Effects Of Resident Species On Recruitment Into A Community: Larval Settlement Versus Post-Settlement Mortality In The Oyster Crassostrea Virginica, Roman Zajac, Richard W. Osman, Robert B. Whitlatch
Effects Of Resident Species On Recruitment Into A Community: Larval Settlement Versus Post-Settlement Mortality In The Oyster Crassostrea Virginica, Roman Zajac, Richard W. Osman, Robert B. Whitlatch
Biology and Environmental Science Faculty Publications
Laboratory and field experiments revealed that a variety of species of common, sessile invertebrates, including barnacles, ascidians, and bryozoans, affected the settlement and post-settlement abundance of the oyster Crassostrea virginica (Gmelin). While the nature of the effects varied, most species both reduced oyster settlement by covering and removing substrate available for attachment, and increased settlement on adjacent surfaces. The solitary ascidians Ciona intestinalis (L.) and Styela clava (Herdman), were found to be predators of oyster larvae. Post-settlement survivorship and growth were also strongly affected by the presence of sessile species. In most cases the effects were negative and correlated with …