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Full-Text Articles in Life Sciences
A Rapid Chromatographic Method For Recovery Of 15no2- And No3- Produced By Nitrification In Aqueous Samples, H Kator, Lj Morris, Rl Wetzel
A Rapid Chromatographic Method For Recovery Of 15no2- And No3- Produced By Nitrification In Aqueous Samples, H Kator, Lj Morris, Rl Wetzel
VIMS Articles
The sensitivity and comparative simplicity of N-15 stable isotopic tracer techniques has been used to quantify rates of nitrification in aquatic systems. However, the most commonly used method for recovery of inorganic oxidized nitrogen compounds from aqueous samples, which is based on liquid-liquid partitioning, is time consuming and contamination prone. We describe a solid-phase rapid chromatographic method for recovery of (NO2-)-N-15 and NO3- produced by nitrification in aqueous samples. Compared to liquid-liquid partitioning, the advantages are significantly reduced processing time and reduced potential for contamination. Typical results are presented for the tidal, freshwater reaches of the James River estuary.
Shelter Selection By Spiny Lobster Under Variable Predation Risk, Social Conditions, And Shelter Size, Db Eggleston, Rom Lipcius
Shelter Selection By Spiny Lobster Under Variable Predation Risk, Social Conditions, And Shelter Size, Db Eggleston, Rom Lipcius
VIMS Articles
Shelter use patterns of den dwelling Caribbean spiny lobster, Panulirus argus, appear to be regulated by predation risk. The risk of predation may be modified by (1) social structure, which alters the effectiveness of communal defense, and (2) the scaling between lobster size and shelter size, which enhances the protective capacity of the den. These hypotheses were tested with field enclosure experiments using artificial lobster shelters, which examined the effects of predation risk (i.e., presence or absence of a major predator, the nurse shark Ginglyostoma cirratum), spiny lobster size, social condition (i.e., presence or absence of conspecifics), and shelter size …
Measurement Of Marine Picoplankton Cell-Size By Using A Cooled, Charge-Coupled Device Camera With Image-Analyzed Fluorescence Microscopy, Cl Viles, Me Sieracki
Measurement Of Marine Picoplankton Cell-Size By Using A Cooled, Charge-Coupled Device Camera With Image-Analyzed Fluorescence Microscopy, Cl Viles, Me Sieracki
VIMS Articles
Accurate measurement of the biomass and size distribution of picoplankton cells (0.2 to 2.0-mu-m) is paramount in characterizing their contribution to the oceanic food web and global biogeochemical cycling. Image-analyzed fluorescence microscopy, usually based on video camera technology, allows detailed measurements of individual cells to be taken. The application of an imaging system employing a cooled, slow-scan charge-coupled device (CCD) camera to automated counting and sizing of individual picoplankton cells from natural marine samples is described. A slow-scan CCD-based camera was compared to a video camera and was superior for detecting and sizing very small, dim particles such as fluorochrome-stained …
Annular Growth Layers In Juvenile Loggerhead Turtles (Caretta-Caretta), Rc Klinger, Ja Musick
Annular Growth Layers In Juvenile Loggerhead Turtles (Caretta-Caretta), Rc Klinger, Ja Musick
VIMS Articles
Juvenile loggerhead turtles (Caretta caretta) were tagged with tetracycline to establish a chronology for deposition of periosteal bone growth layers. Eight recaptures, encompassing intervals of 1 to 3 years, were used to demonstrate that these growth layers were typically deposited on an annual basis. However, the number of scorable growth layers represents an underestimate of true age because earlier growth layers are obscured by expansion of the medullary cavity during growth. The number of absorbed growth layers was extrapolated from calculations based on juvenile bone growth patterns. Most (83%) of these corrected age estimates for juvenile loggerheads, 40 to 80 …
Density-Dependent Predation By Blue Crabs Upon Infaunal Clam Species With Contrasting Distribution And Abundance Patterns, Db Eggleston, Rom Lipcius, Ah Hines
Density-Dependent Predation By Blue Crabs Upon Infaunal Clam Species With Contrasting Distribution And Abundance Patterns, Db Eggleston, Rom Lipcius, Ah Hines
VIMS Articles
Adult infaunal clams (Macoma balthica) persist at low densities in sandy and muddy habitats in Chesapeake Bay, USA, despite intense predation by blue crabs Callinectes sapidus; another infaunal soft-shelled clam (Mya arenaria) only persists in sandy habitats. We hypothesized that the persistence of M. balthica and M. arenaria in certain habitats was due to blue crabs exhibiting a type III (sigmoid) functional response whereby the risk of mortality is reduced at low clam densities. Laboratory experiments assessed functional responses (prey consumption predator-1 as a function of prey density) of large male blue crabs to 6 densities of M. balthica as …
Relationship Of Habitat And Spatial Scale With Physiological State And Settlement Of Blue Crab Postlarvae In Chesapeake Bay, Ks Metcalf, Rom Lipcius
Relationship Of Habitat And Spatial Scale With Physiological State And Settlement Of Blue Crab Postlarvae In Chesapeake Bay, Ks Metcalf, Rom Lipcius
VIMS Articles
Physiological state (molt stage) of planktonic and benthic blue crab (Callinectes sapidus) postlarvae (megalopae) was quantified within and outside Chesapeake Bay at various spatial scales. Physiological state of planktonic megalopae advanced significantly from the continental shelf off the Chesapeake Bay mouth, through the bay mainstem, and into upriver stations in the York River, a tributary of Chesapeake Bay. These results imply that settlement and metamorphosis of blue crab megalopae is dependent on location relative to the shelf. The physiological evidence supports the export-reinvasion theory of blue crab recruitment and is inconsistent with a larval retention hypothesis. In the tributary, benthic …
Index Of Papers Published In The Journal Of Shellfish Research Volumes 1-10 (1981-1991), Michael Castagna, Nancy Lewis, Charles Mcfadden, Mary Gibbons
Index Of Papers Published In The Journal Of Shellfish Research Volumes 1-10 (1981-1991), Michael Castagna, Nancy Lewis, Charles Mcfadden, Mary Gibbons
VIMS Articles
No abstract provided.