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Articles 1 - 16 of 16

Full-Text Articles in Life Sciences

Degradation Kinetics Of Aromatic Organic Solutes Introduced Into A Heterogeneous Aquifer, Wg Macintyre, M Boggs, Cp Antworth, Tb Stauffer Dec 1993

Degradation Kinetics Of Aromatic Organic Solutes Introduced Into A Heterogeneous Aquifer, Wg Macintyre, M Boggs, Cp Antworth, Tb Stauffer

VIMS Articles

Degradation rates of benzene, p-xylene, naphthalene, and o-dichlorobenzene have been measured in a heterogeneous, unconfined aquifer during a pulse injection experiment at Columbus Air Force Base, Columbus, Mississippi. Dissolved oxygen in the pulse plume maintained aerobic conditions. Degradation kinetics calculated from the complete field data set were approximately first order with the following rate constants: benzene, 0.0070 d-1; p-xylene, 0.0107 d-1; naphthalene, 0.0064 d-1; and o-dichlorobenzene, 0.0046 d-1. Reaction rates were also calculated from a near-field subset of the data using a model based on the hydrologic characteristics of the aquifer. Shapes of the degradation rate ...


Biological And Hydrodynamic Regulation Of The Microbial Food-Web In A Periodically Mixed Estuary, Pm Eldridge, Me Sieracki Dec 1993

Biological And Hydrodynamic Regulation Of The Microbial Food-Web In A Periodically Mixed Estuary, Pm Eldridge, Me Sieracki

VIMS Articles

Abundances of chroococcoid cyanobacteria and heterotrophic bacteria in surface waters of the York River subestuary covary with spring-neap tidally induced changes in the mixed-layer depth. Abundances of their principal grazers, heterotrophic protists, however, do not oscillate. A simulation model of this system using nonlinear, density-dependent functions has been developed to replicate cycles observed in the two bacterial abundances and simulate bacterial production and protistan grazing. A Jassby-Plan equation is used to determine growth rate from the mean mixed-layer light and empirically derived growth and a parameters. Changes in mixed-layer depth regulate light availability, thereby controlling cyanobacterial growth rates. The model ...


Perkinsus Marinus Susceptibility And Defense-Related Activities In Eastern Oysters Crassostrea Virginica: Temperature Effects, Fu-Lin E. Chu, Jerome F. La Peyre Sep 1993

Perkinsus Marinus Susceptibility And Defense-Related Activities In Eastern Oysters Crassostrea Virginica: Temperature Effects, Fu-Lin E. Chu, Jerome F. La Peyre

VIMS Articles

he relationship of potential defense-related cellular and humoral activities and the sus- ceptibility of eastern oysters Crassostrea virginica to the parasite Perkinsus marinus were examined at 10, 15, 20 and 25 "C. Oysters were acclimated at experimental temperatures for 20 d and then chal- lenged with R marinus. Total hemocyte counts (TC) and percentage of granulocytes (PG) 20 d after temperature acclimation were higher in oysters at high than at low acclimation temperature. Higher protein (P) and lysozyme (L) concentrations were found in oysters at 10 and 15 "C. No significant differ- ences in hemagglutination (H) titers due to temperature ...


Index Of Papers Published In The Proceedings Of The National Shellfisheries Association, Roger Mann, Elaine M. Lynch, Michael Castagna, Bernadita M. Campos, Nancy Lewis Jan 1993

Index Of Papers Published In The Proceedings Of The National Shellfisheries Association, Roger Mann, Elaine M. Lynch, Michael Castagna, Bernadita M. Campos, Nancy Lewis

VIMS Articles

No abstract provided.


Effects Of 2 Bloom-Forming Dinoflagellates, Prorocentrum-Minimum And Gyrodinium-Uncatenum, On The Growth And Survival Of The Eastern Oyster, Crassostrea-Virginica (Gmelin 1791), Mark Luckenbach, Kg Sellner, Se Shumway, K Greene Jan 1993

Effects Of 2 Bloom-Forming Dinoflagellates, Prorocentrum-Minimum And Gyrodinium-Uncatenum, On The Growth And Survival Of The Eastern Oyster, Crassostrea-Virginica (Gmelin 1791), Mark Luckenbach, Kg Sellner, Se Shumway, K Greene

VIMS Articles

Laboratory experiments were conducted to investigate the effects of the dinoflagellates Prorocentrum minimum and Gyrodinium uncatenum on the growth and survival of juvenile eastern oysters, Crassostrea virginica. In separate experiments lasting 30 d and 18 d for P. minimum and G. uncatenum, respectively, the dinoflagellates were offered to the oysters in both unialgal and mixed diets (with the diatom Thalassiosira weisflogii). Eight diets were used in each experiment: (i) the dinoflagellate at bloom density, (ii) the dinoflagellate at 33% bloom density, (iii) the dinoflagellate at 5% bloom density, (iv-vi) the diatom at the above densities, (vii) 50% dinoflagellate bloom density ...


Evaluation Of In-Situ Silhouette Photography In Investigations Of Estuarine Zooplankton And Ichthyoplankton, Je Olney, Ed Houde Jan 1993

Evaluation Of In-Situ Silhouette Photography In Investigations Of Estuarine Zooplankton And Ichthyoplankton, Je Olney, Ed Houde

VIMS Articles

Trials of a paired-net towing frame fitted with a submersible 35-mm camera system were conducted in Chesapeake Bay in 1989-1990 to 1) demonstrate the use and efficiency of in situ silhouette photography in studies of estuarine zooplankton and ichthyoplankton; 2) determine the taxonomic potential of in situ silhouette photography in several estuarine habitats; and 3) compare estimates of plankton density from in situ silhouette photographs with concurrent preserved net collections. Time required to split, sort and enumerate plankton in preserved samples was 2-75 h per sample longer than the time required to view and enumerate silhouettes on film. Ninety-four taxa ...


Effect Of Salinity On Infection Progression And Pathogenicity Of Perkinsus-Marinus In The Eastern Oyster, Crassostrea-Virginica (Gmelin), Lisa M. Ragone, Eugene M. Burreson Jan 1993

Effect Of Salinity On Infection Progression And Pathogenicity Of Perkinsus-Marinus In The Eastern Oyster, Crassostrea-Virginica (Gmelin), Lisa M. Ragone, Eugene M. Burreson

VIMS Articles

The effect of salinity on Perkinsus marinus, a protozoan pathogen of the eastern oyster, Crassostrea virginica (Gmelin 1791) was investigated. Oysters parasitized by P. marinus were exposed in the laboratory to 6, 9, 12, and 20 ppt at a temperature ranging from 20-25-degrees-C, for an eight week period. Infection prevalence and intensity were assessed in samples (n = 25) from each treatment following 2, 4, 6, and 8 weeks of exposure and oyster mortality was determined daily. The pathogen persisted, at high prevalences, throughout the course of the experiment at all treatment salinities; however, P. marinus infection development was retarded at ...


Spatial And Temporal Bacterioplankton Dynamics During Destratification Of The James River Estuary, Virginia, Usa, Et Koepfler, Hi Kator, Rl Wetzel, Lw Haas Jan 1993

Spatial And Temporal Bacterioplankton Dynamics During Destratification Of The James River Estuary, Virginia, Usa, Et Koepfler, Hi Kator, Rl Wetzel, Lw Haas

VIMS Articles

Bacterioplankton abundance and production were examined over the course of a destratification event in the lower James River, Virginia, USA, Goals of the study were to determine if destratification would influence temporal patterns of bacterioplankton parameters and relationships between bacterioplankton and other biological and abiological parameters. Mean bacterial abundance grouped over stations did not change over the course of the study, and were characterized by much smaller coefficients of variation than all other planktonic constituents. However, bacterial production measured by H-3-thymidine (H-3-Tdr) incorporation decreased significantly from a stratified (324 mu g Cl-1 d(-1)) to a destratified (187 mu g ...


Phylogeny Of The Epinephelinae (Teleostei, Serranidae), Cc Baldwin, Gd Johnson Jan 1993

Phylogeny Of The Epinephelinae (Teleostei, Serranidae), Cc Baldwin, Gd Johnson

VIMS Articles

Relationships among epinepheline genera are investigated based on cladistic analysis of larval and adult morphology. Five monophyletic tribes are delineated, and relationships among tribes and among genera of the tribe Grammistini are hypothesized. Generic composition of tribes differs from Johnson's (1983) classification only in the allocation of Jeboehlkia to the tribe Grammistini rather than the Liopropomini. Despite the presence of the skin toxin grammistin in the Diploprionini and Grammistini, we consider the latter to be the sister group of the Liopropomini. This hypothesis is based, in part, on previously unrecognized larval features. Larval morphology also provides evidence of monophyly ...


Phylogeny Of Lampridiform Fishes, Je Olney, Gd Johnson, Cc Baldwin Jan 1993

Phylogeny Of Lampridiform Fishes, Je Olney, Gd Johnson, Cc Baldwin

VIMS Articles

A survey of characters defining the Neoteleostei, Eurypterygii, Ctenosquamata, Acanthomorpha, Paracanthopterygii and Acanthopterygii convincingly places the Lampridiformes within the acanthomorph clade. Lampridiforms are primitive with respect to the Percomorpha but their precise placement among basal acanthomorphs remains unclear. In the absence of a specific sister-group hypothesis, Polymixia, percopsiform and beryciform taxa were used as outgroups in a cladistic analysis of the order. Monophyly of Lampridiformes is supported by four apomorphies; three are correlated modifications related to the evolution of a unique feeding mechanism in which the maxilla slides forward with the premaxilla during jaw protrusion. The Veliferidae are the sister ...


Identification And Distribution Of Urophycis And Phycis (Pisces, Gadidae) Larvae And Pelagic Juveniles In The United-States Middle Atlantic Bight, Bruce H. Comyns, George C. Grant Jan 1993

Identification And Distribution Of Urophycis And Phycis (Pisces, Gadidae) Larvae And Pelagic Juveniles In The United-States Middle Atlantic Bight, Bruce H. Comyns, George C. Grant

VIMS Articles

Analysis of surface and subsurface plankton collections in the Middle Atlantic Bight (MAB) yielded larvae and juveniles of Phycis chesteri and five species of Urophycis. Identification was based on numbers of epibranchial gill rakers, abdominal vertebrae, and. fin rays (dorsal, caudal, pelvic), patterns of pterygiophore interdigitation, and morphometric characters including body depth at the vent and a ratio between height of the pelvic-fin base and length of the mandible. Urophycis tenuis accounted for 99% of the Urophycis larvae and pelagic juveniles collected during spring off Virginia and New Jersey and was most abundant offshore. Urophycis tenuis larvae were smallest at ...


Age, Growth, And Reproduction Of Tautog Tautoga-Onitis (Labridae, Perciformes) From Coastal Waters Of Virginia, E. Brian Hostetter, Thomas A. Munroe Jan 1993

Age, Growth, And Reproduction Of Tautog Tautoga-Onitis (Labridae, Perciformes) From Coastal Waters Of Virginia, E. Brian Hostetter, Thomas A. Munroe

VIMS Articles

Tautog Tautoga onitis are gaining popularity in Virginia's coastal waters as a recreational and food fish. Adult tautog are seasonally abundant on inshore hard-bottom habitats (1-10 m) and inhabit offshore areas (10-75 m) year-round. Juveniles, especially newly-settled recruits, inhabit vegetated areas in shallow water (usually < 1 m). From March 1979 to July 1986, tautog were collected in lower Chesapeake Bay and nearby coastal waters to examine age, growth, and sexual maturation. Age estimates were determined from annular marks on opercle bones: 82% of the fish were age-10 or younger, 18% exceeded age-10, and 1% were age-20 or older. Marginal increment analysis revealed that annuli formed concurrent with a protracted spawning season (April-July). The von Bertalanffy growth equation, derived from back-calculated mean lengths-at-age, was l(t) = 742 [1-e-0.085 (t-1.816)]. Tautog are long-lived (25+ yr) and attain relatively large sizes (672 mm TL) slowly (K for sexes combined = 0.085). Growth rates of both sexes are similar, although males grow slightly faster (K = 0.090 vs. 0.085 for females). Maturity occurs at age-3 in both sexes. Growth rates for tautog from Virginia are similar to those reported nearly 25 years ago for tautog in Rhode Island. Growth rates for tautog are similar to those of other reef fishes, such as snappers and groupers. Habitat restriction, slow growth, great longevity, and increasing popularity by user groups may contribute to over-exploitation of this species in Virginia waters.


Spatial And Temporal Occurrence Of Spanish Mackerel Scomberomorus-Maculatus In Chesapeake Bay, Mark E. Chittenden, Luiz R. Barbieri, Cynthia M. Jones Jan 1993

Spatial And Temporal Occurrence Of Spanish Mackerel Scomberomorus-Maculatus In Chesapeake Bay, Mark E. Chittenden, Luiz R. Barbieri, Cynthia M. Jones

VIMS Articles

No abstract provided.


A New Method Of Oocyte Separation And Preservation For Fish Reproduction Studies, Susan K. Lowerre-Barbieri, Luiz R. Barbieri Jan 1993

A New Method Of Oocyte Separation And Preservation For Fish Reproduction Studies, Susan K. Lowerre-Barbieri, Luiz R. Barbieri

VIMS Articles

No abstract provided.


Estimation Of Oyster Shell Surface-Area Using Regression Equations Derived From Aluminum Foil Molds, Reinaldo Morales-Alamo Jan 1993

Estimation Of Oyster Shell Surface-Area Using Regression Equations Derived From Aluminum Foil Molds, Reinaldo Morales-Alamo

VIMS Articles

A method is described for estimation of surface area of shells of the American oyster, Crassostrea virginica (Gmelin 1791), as an alternative to direct measurement of surface area with aluminum foil molds. It is based on computation, from a small sample of shells, of the equation for regression of area of aluminum foil molds of shells on area enclosed within tracings of the shell outline. Area of other shells is then predicted from their shell outline area using the equation. Accuracy of the regression method in spatfall studies was established using data from shellstring collectors suspended in the Piankatank River ...


Development Of Disease Caused By The Parasite, Perkinsus-Marinus And Defense-Related Hemolymph Factors In 3 Populations Of Oysters From The Chesapeake Bay, Usa, Fu-Lin C. Chu, J.F. La Peyre Jan 1993

Development Of Disease Caused By The Parasite, Perkinsus-Marinus And Defense-Related Hemolymph Factors In 3 Populations Of Oysters From The Chesapeake Bay, Usa, Fu-Lin C. Chu, J.F. La Peyre

VIMS Articles

The development of infection caused by the protozoan parasite, Perkinsus marinus (Dermo) and some specific potential defense-related cellular and humoral components in oysters collected from three geographic areas, Deepwater Shoal of James River (DW), Wachapreague (WP), and Mobjack Bay (MJ) were examined over time. Oysters were maintained in estuarine water (salinity = 20 ppt) or in water at a salinity similar to the ambient salinity of the collection sites. Oysters were sampled at the initiation of the experiment (day 0), day 35, and day 100 to determine defense-related parameters and disease prevalence and intensity. All populations experienced a significant increase in ...