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Full-Text Articles in Life Sciences
Perkinsus Marinus Extracellular Protease Modulates Survival Of Vibrio Vulnificus In Eastern Oyster (Crassostrea Virginica) Hemocytes, Bd Tall, Jf La Peyre, Et Al, M Faisal
Perkinsus Marinus Extracellular Protease Modulates Survival Of Vibrio Vulnificus In Eastern Oyster (Crassostrea Virginica) Hemocytes, Bd Tall, Jf La Peyre, Et Al, M Faisal
VIMS Articles
The in vitro effects of the Perkinsus marinus serine protease on the intracellular survival of Vibrio vulnificus in oyster hemocytes were examined by using a time-course gentamicin internalization assay. Results showed that protease-treated hemocytes were initially slower to internalize V. vulnificus than untreated hemocytes. After 1 h, the elimination of V. vulnificus by treated hemocytes was significantly suppressed compared with hemocytes infected with invasive and noninvasive controls. Our data suggest that the serine protease produced by P. marinas suppresses the vibriocidal activity of oyster hemocytes to effectively eliminate V. vulnificus, potentially leading to conditions favoring higher numbers of vibrios in …
Non-Redfield Carbon And Nitrogen Cycling In The Arctic: Effects Of Ecosystem Structure And Dynamics, Kendra L. Daly, Douglas W.R. Wallace, Walker O. Smith Jr., Annelie Skoog, Ruben Lara, Michel Gosselin, Eva Falck, Patricia L. Yager
Non-Redfield Carbon And Nitrogen Cycling In The Arctic: Effects Of Ecosystem Structure And Dynamics, Kendra L. Daly, Douglas W.R. Wallace, Walker O. Smith Jr., Annelie Skoog, Ruben Lara, Michel Gosselin, Eva Falck, Patricia L. Yager
VIMS Articles
The C:N ratio is a critical parameter used in both global ocean carbon models and field studies to understand carbon and nutrient cycling as well as to estimate exported carbon from the euphotic zone. The so-called Redfield ratio (C:N = 6.6 by atoms) [Redfield et nl., 1963] is widely used for such calculations. Here we present data from the NE Greenland continental shelf that show that most of the C:N ratios for particulate (autotrophic and heterotrophic) and dissolved pools and rates of transformation among them exceed Redfield proportions from June to August, owing to species composition, size, and biological interactions. …
Selective Feeding Behavior Of Larval Naked Gobies Gobiosoma Bosc And Blennies Chasmodes Bosquianus And Hypsoblennius Hentzi: Preferences For Bivalve Veligers, Jm Harding
VIMS Articles
Naked gobies Gobiosoma bose, striped blennies Chasmodes bosquianus, and feather blennies Hypsoblennius hentzi provide important intermediate links within the trophic structure of estuarine oyster reef communities. Predator-prey interactions between planktonic larvae of these fishes and larval eastern oysters Crassostrea virginica may influence recruitment success within oyster reef communities. These 3 species of oyster reef fish larvae were cultured from wild nests and used in multifactorial laboratory feeding experiments with larval oysters or hard clams Mercenaria mercenaria as well as wild plankton as prey items to determine the effects of predator age, predator concentration, and prey type on feeding selectivity of …
Ontogenetic Changes In Habitat Use By Postlarvae And Young Juveniles Of The Blue Crab, Ra Pardieck, R J. Orth, R. J. Diaz, Rom Lipcius
Ontogenetic Changes In Habitat Use By Postlarvae And Young Juveniles Of The Blue Crab, Ra Pardieck, R J. Orth, R. J. Diaz, Rom Lipcius
VIMS Articles
Changing habitat requirements are evident during the developmental cycles of many species. In this field investigation, we attempted to distinguish between depth (shallow vs deep), habitat structure (seagrass species), and study site as factors influencing the distribution and abundance of postlarvae and juvenile blue crabs Callinectes sapidus in the Chesapeake Bay. Deep (greater than or equal to 70 cm mean low water [MLW]) and shallow (less than or equal to 50 cm MLW) suction samples in monospecific Zostera marina and Ruppia maritima beds were taken in the York River, a tributary of the Chesapeake Bay. Our studies revealed ontogenetic changes …
Estimation Of Bacterial Respiration And Growth Efficiency In The Ross Sea, Antarctica, C. A. Carlson, N. R. Bates, H. W. Ducklow, D. A. Hansell
Estimation Of Bacterial Respiration And Growth Efficiency In The Ross Sea, Antarctica, C. A. Carlson, N. R. Bates, H. W. Ducklow, D. A. Hansell
VIMS Articles
Seawater cultures were conducted in large volume (36 l) gas impermeable tri-laminate bags for the purpose of empirically deriving bacterial growth efficiency (BGE) and carbon conversion factors (CCF) in the south central Ross Sea. This experimental design allowed for concomitant measurements of metabolic reactants (loss of total and dissolved organic carbon [TOC and DOG]) and products (gain of total carbon dioxide [TCO2] and bacterial biomass) to be made from a single incubation vessel. Some previous studies have relied on proxy measurements (e.g. O-2, H-3-thymidine incorporation and cell abundance) to determine BGE and CCF rather than direct carbon measurements. Our experimental …
Bacterial Growth In Experimental Plankton Assemblages And Seawater Cultures From The Phaeocystis Antarctica Bloom In The Ross Sea, Antarctica, H. W. Ducklow, C. Carlson, Walker O. Smith Jr.
Bacterial Growth In Experimental Plankton Assemblages And Seawater Cultures From The Phaeocystis Antarctica Bloom In The Ross Sea, Antarctica, H. W. Ducklow, C. Carlson, Walker O. Smith Jr.
VIMS Articles
A series of seawater culture experiments was carried out during the Phaeocystis antarctica bloom in the Ross Sea polynya (76.5 degrees S, 180 degrees W; November to December 1994 and December 1995 to January 1996) to examine bacterioplankton growth and derive empirical factors for estimating bacterial production rates. Bacterial growth was exponential over 3 to 10 d in all experiments, at rates of ca 0.1 to 0.7 d(-1), even in persistently cold waters (-2 to + 1 degrees C). Growth rates were lower in the early part of the bloom (early to mid-November) and highest during the period of peak …
Phytoplankton Growth Rates In The Ross Sea, Antarctica, Determined By Independent Methods: Temporal Variations, Walker O. Smith Jr., D. M. Nelson, S. Mathot
Phytoplankton Growth Rates In The Ross Sea, Antarctica, Determined By Independent Methods: Temporal Variations, Walker O. Smith Jr., D. M. Nelson, S. Mathot
VIMS Articles
The development of the seasonal phytoplankton bloom in the Ross Sea was studied during two cruises. The first, conducted in November-December 1994, investigated the initiation and rapid growth of the bloom, whereas the second (December 1995-January 1996) concentrated on the bloom's maximum biomass period and the subsequent decline in biomass. Central to the understanding of the controls of growth and the summer decline of the bloom is a quantitative assessment of the growth rate of phytoplankton. Growth rates were estimated over two time scales with different methods. The first estimated daily growth rates from isotopic incorporation under simulated in situ …
The Bacterial Component Of The Oceanic Euphotic Zone, H. W. Ducklow
The Bacterial Component Of The Oceanic Euphotic Zone, H. W. Ducklow
VIMS Articles
Bacteria in the open sea remote from land are sustained strictly on local sources of organic production which should make understanding their nutrition and growth regulation easier than in nearshore systems, estuaries and lakes. Until now, a paucity of data from geographically isolated oceanic sites prevented ready :interpretation. In the past decade investigation of bacterial properties in oceanic systems has increased rapidly, stimulated in part by large oceanographic programs like the Joint Global Ocean Flux Study. Here I review comprehensive investigations of bacterial biomass and production dynamics in the subarctic north Atlantic and north Pacific, oligotrophic gyres in both oceans, …
Comparative Field Study Of Crassostrea Gigas (Thunberg, 1793) And Crassostrea Virginica (Gmelin, 1791) In Relation To Salinity In Virginia, Gustavo W. Calvo, Mark Luckenbach, Standish K. Allen, Eugene Burreson
Comparative Field Study Of Crassostrea Gigas (Thunberg, 1793) And Crassostrea Virginica (Gmelin, 1791) In Relation To Salinity In Virginia, Gustavo W. Calvo, Mark Luckenbach, Standish K. Allen, Eugene Burreson
VIMS Articles
To evaluate and compare the performance of triploid juvenile C. gigas (mean shell height = 19.2 mm) and triploid juvenile Crassostrea virginica (mean shell height = 31.7 mm), 600 oysters of each species were deployed for 1 year in floating mesh cages at three replicate sites within low, medium, and high salinity regimes (respectively,25%) in the Chesapeake Bay and the Atlantic Coast of Virginia. The comparative performance of the two oyster species varied with salinity. At low salinity sites, cumulative mortality of C. virginica (10%) was significantly (P < .05) lower than that of C. gigas (63%), and over-all mean growth rate of C. virginica (2.9 mm mo(-1)) was significantly (P < .05) higher than that of C. gigas (1.6 mm mo(-1)). At medium salinity sites, survival and growth rate of C. virginica and C. gigas were nor significantly (P > .05) different. Both species experienced moderately high cumulative mortality at the medium …
Abundance And Vertical Distribution Of Drifting, Post-Larval Macoma Spp. (Bivalvia : Tellinidae) In The York River, Virginia, Usa, Lp Garrison, Ja Morgan
Abundance And Vertical Distribution Of Drifting, Post-Larval Macoma Spp. (Bivalvia : Tellinidae) In The York River, Virginia, Usa, Lp Garrison, Ja Morgan
VIMS Articles
We sampled the early drifting post-larvae of a complex of 2 species of tellinid bivalves, Macoma spp., at a station in the lower York River, Chesapeake Bay, USA. Plankton samples were collected by pump every 3 h from 3 depths (surface, mid-depth, and bottom) on 4 dates corresponding to full and new moons. Macoma spp. post-larvae (size range 400 to 500 mu m) were abundant in the plank ton throughout the sampling period. The environmental factors influencing the abundance and vertical distribution of drifting post-larvae were evaluated using linear and logistic regression. Post-larvae were always more abundant during night as …
Vertical Migration Behavior And Larval Transport In Brachyuran Crabs, Lp Garrison
Vertical Migration Behavior And Larval Transport In Brachyuran Crabs, Lp Garrison
VIMS Articles
I documented the patterns of vertical distribution and abundance of zoeae from 3 families of brachyuran crabs in the York River, a sub-estuary in southern Chesapeake Bay (USA). The family groups included species from Ocypodidae, Pinnotheridae, and Panopeidae. I assessed the effects of Light and tidal current stage on the abundance and vertical distribution of zoeae using analysis of variance (ANOVA) and logistic regression. Clear behavioral patterns were evident in the logistic regression. Ocypodid larvae exhibited tidally timed behavior with larvae nearest the surface during ebb tides. Pinnotherid larval behaviors were correlated with both light and tidal current phase. Larvae …