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VIMS Articles

2003

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Articles 1 - 30 of 49

Full-Text Articles in Life Sciences

Isolation And Characterization Of Serine Protease Gene(S) From Perkinsus Marinus, Gd Brown, Kimberly S. Reece Nov 2003

Isolation And Characterization Of Serine Protease Gene(S) From Perkinsus Marinus, Gd Brown, Kimberly S. Reece

VIMS Articles

This study reports the first serine protease gene(s) isolated from Perkinsus marinus. Using universal primers, a 518 bp subtilisin-like serine protease gene fragment was amplified from P, marinus genomic DNA and used as a probe to screen a lambda-phage P. marinus genomic library; 2 different gamma-phage clones hybridized to the digoxigenin(DIG)-labeled subtilisin-like gene fragment. Following subcloning and sequencing of the larger DNA fragment, a 1254 bp open reading frame was identified and later confirmed, by 5' and 3' random amplification of cDNA ends (RACE) and northern blot analysis, to contain the entire coding-region sequence. Sequence analysis of ...


Form And Function Of The Bulbus Arteriosus In Yellowfin Tuna (Thunnus Albacares), Bigeye Tuna (Thunnus Obesus) And Blue Marlin (Makaira Nigricans): Static Properties, M H. Braun, Richard Brill, J M. Gosline, D R. Jones Oct 2003

Form And Function Of The Bulbus Arteriosus In Yellowfin Tuna (Thunnus Albacares), Bigeye Tuna (Thunnus Obesus) And Blue Marlin (Makaira Nigricans): Static Properties, M H. Braun, Richard Brill, J M. Gosline, D R. Jones

VIMS Articles

The juxtaposition of heart and gills in teleost fish means that the Windkessel function characteristic of the whole mammalian arterial tree has to be subserved by the extremely short ventral aorta and bulbus arteriosus. Over the functional pressure range, arteries from blue marlin (Makaira nigricans) and yellowfin tuna (Thunnus albacares) have J-shaped pressure-volume (P-V) loops, while bulbi from the same species have r-shaped P-V loops, with a steep initial rise followed by a compliant plateau phase. The steep initial rise in pressure is due to the geometry of the lumen. The interactions between radius, pressure and tension require a large ...


Form And Function Of The Bulbus Arteriosus In Yellowfin Tuna (Thunnus Albacares): Dynamic Properties, M. H. Braun, Richard Brill, J. M. Gosline, D. R. Jones Oct 2003

Form And Function Of The Bulbus Arteriosus In Yellowfin Tuna (Thunnus Albacares): Dynamic Properties, M. H. Braun, Richard Brill, J. M. Gosline, D. R. Jones

VIMS Articles

The bulbus arteriosus of the teleost heart possesses a static inflation curve that is r-shaped over the in vivo pressure range. To examine the possible significance of this in living animals, we recorded arterial blood pressure from anaesthetized yellowfin tuna and utilized a video dimensional analyser to simultaneously record changes in bulbar diameter. By plotting the changes in pressure against the changes in diameter, it was possible to create dynamic pressure-diameter (P-D) loops as well as calculate the instantaneous volume changes within the bulbus. The dynamic P-D loops showed the same features exhibited by static inflation. When nearly empty, a ...


Abundance And Distribution Of Planktonic Archaea And Bacteria In The Waters West Of The Antarctic Peninsula, Matthew Church, Edward F. Delong, Hugh Ducklow, Markus Karner, Christian Preston, David M. Karl Sep 2003

Abundance And Distribution Of Planktonic Archaea And Bacteria In The Waters West Of The Antarctic Peninsula, Matthew Church, Edward F. Delong, Hugh Ducklow, Markus Karner, Christian Preston, David M. Karl

VIMS Articles

Polyribonucleotide probes targeting planktonic archaeal (Group I and II) and bacterial rRNA revealed that Archaea comprised a significant fraction of total prokaryote cell abundance in the marine waters west of the Antarctic Peninsula. Determinations of Archaea and Bacteria cell abundances were made during two research cruises to the Palmer Long‐Term Ecological Research region during the austral winter and summer of 1999. During the austral summer, surface water abundances of Group I (GI) Archaea were generally low, averaging 4.7 x 103 cells ml−1 and accounting for 1% of the total picoplankton assemblage. The abundance of GI Archaea increased ...


A Novel Tag-Recovery Model With Two Size Classes For Estimating Fishing And Natural Mortality, With Implications For The Southern Rock Lobster (Jasus Edwardsii) In Tasmania, Australia, Rj Latour, Jm Hoenig, Da Hepworth, Sd Frusher Sep 2003

A Novel Tag-Recovery Model With Two Size Classes For Estimating Fishing And Natural Mortality, With Implications For The Southern Rock Lobster (Jasus Edwardsii) In Tasmania, Australia, Rj Latour, Jm Hoenig, Da Hepworth, Sd Frusher

VIMS Articles

Multi-year tag-recovery models can be used to derive estimates of age- and year-specific annual survival rates and year-specific instantaneous fishing and natural mortality rates. The latter, which are often of interest to fisheries managers, usually can only be estimated when the tag-reporting rate (lambda) and the short-term tag-induced mortality and tag-shedding rate (phi) are known a priori. We present a new multi-year tagging model that permits estimation of instantaneous mortality rates independently of philambda provided tagged animals from two adjacent size groups are released simultaneously. If the two size groups comprise animals just above and below the minimum harvestable size ...


Systematic Evaluation Of Factors Controlling Perkinsus Marinus Transmission Dynamics In Lower Chesapeake Bay, Lm Ragone Calvo, Cf Dungan, Bs Roberson, Em Burreson Aug 2003

Systematic Evaluation Of Factors Controlling Perkinsus Marinus Transmission Dynamics In Lower Chesapeake Bay, Lm Ragone Calvo, Cf Dungan, Bs Roberson, Em Burreson

VIMS Articles

The transmission of Perkinsus marinus in eastern oysters Crassostrea virginica in relation to water temperature, host oyster mortality, and water-column abundance of anti-P. marinus antibody-labeled cells was systematically examined for 20 mo at a site in the lower York River, Virginia, USA. Uninfected sentinel oysters were naturally exposed to the parasite at 2 wk intervals throughout the course of the study to determine the periodicity and rates of parasite transmission. The timing and magnitude of disease-associated oyster mortalities in a local P. marinus-infected oyster population were estimated by monitoring a captive subset of the local oyster population. Flow cytometric immunodetection ...


Detection Of The Oyster Parasite Bonamia Ostreae By Fluorescent In Situ Hybridization, Ryan Carnegie, Bj Barber, Dl Distel Aug 2003

Detection Of The Oyster Parasite Bonamia Ostreae By Fluorescent In Situ Hybridization, Ryan Carnegie, Bj Barber, Dl Distel

VIMS Articles

Bonamia ostreae is an economically significant protistan parasite of the flat oyster Ostrea edulis in Europe and North America. Management of this parasite depends partly upon its reliable identification in wild and aquacultured oyster populations, but B. ostreae is small and difficult to detect by traditional microscopic methods. We designed a fluorescent in situ hybridization (FISH) assay to sensitively detect B. ostreae in standard histopathological sections of B. ostreae-infected oysters using fluorescently labeled DNA oligonucleotide probes. Hybridization using a cocktail of 3 presumptively B. ostreae-specific, fluorescein iso(thio)cyanate (FITC)-labeled oligonucleotides produced an unambiguous staining pattern of small green ...


Grazing And Colony Size Development In Phaeocystis Globosa (Prymnesiophyceae): The Role Of A Chemical Signal, K Tang Jul 2003

Grazing And Colony Size Development In Phaeocystis Globosa (Prymnesiophyceae): The Role Of A Chemical Signal, K Tang

VIMS Articles

The bloom-forming prymnesiophyte Phaeocystis globosa forms hollow, spherical, mucilaginous colonies that vary from micrometres to millimetres in size. A recent paper gave the first empirical evidence that colony size increase in P. globosa is a defensive response against grazers, and knowing the signalling mechanism(s) behind this response will thus be a key to understanding the trophodynamics in systems dominated by this species. I conducted experiments with specially designed diffusion incubators, each of which consists of a non-grazing chamber (with P. globosa only) and a grazing chamber (grazers + phytoplankton) connected by 2 mum polycarbonate membrane filters. The results showed that ...


Influence Of Habitat On Diet And Distribution Of Striped Bass (Morone Saxatilis) In A Temperate Estuary, Jm Harding, Roger L. Mann May 2003

Influence Of Habitat On Diet And Distribution Of Striped Bass (Morone Saxatilis) In A Temperate Estuary, Jm Harding, Roger L. Mann

VIMS Articles

Striped bass (Morone saxatilis) are recreationally and commercially valuable finfish along the Atlantic seaboard of North America including the Chesapeake Bay estuary. Habitat use patterns for striped bass in relation to biogenic habitat types in Chesapeake Bay tributaries are poorly described although it is widely acknowledged that these piscivorous fishes use estuarine habitat for nursery and feeding grounds during development. Striped bass diet and distribution patterns were examined in relation to a gradient of biogenic habitats ranging from complex three-dimensional oyster reef through flat oyster bar to sand bottom habitat in the Piankatank River, Virginia. Striped bass were more abundant ...


Observations On The Distribution Of Meroplankton During An Upwelling Event, Al Shanks, J Largier, J Brubaker May 2003

Observations On The Distribution Of Meroplankton During An Upwelling Event, Al Shanks, J Largier, J Brubaker

VIMS Articles

The distribution of the larvae of benthic invertebrates was investigated relative to hydrographic structures as a test of the hypothesi's that larvae behave as if they are passive particles. Observations of larval and oceanographic distributions were made off Duck, North Carolina, USA in August 1994. Conditions were characterized by wind-driven coastal upwelling;flow was generally offshore near the surface and onshore below the pycnocline. Within 5 km of the shore the pycnocline was bent upward by the upwelling and it intersected the surface along most of the transects. In zooplankton samples, 20 taxa of larvae were counted (10 bivalve ...


Mikrocytos Roughleyi Taxonomic Affiliation Leads To The Genus Bonamia (Haplosporidia), N Cochennec-Laureau, Kimberly S. Reece, Fcj Berthe, Pm Hine Apr 2003

Mikrocytos Roughleyi Taxonomic Affiliation Leads To The Genus Bonamia (Haplosporidia), N Cochennec-Laureau, Kimberly S. Reece, Fcj Berthe, Pm Hine

VIMS Articles

Microcell-type parasites of oysters are associated with a complex of diseases in different oyster species around the world. The etiological agents are protists of very small size that are very difficult to characterize taxonomically. Associated lesions may vary according to the host species, and their occurrence may be related to variations in tissue structure. Lesion morphology cannot be used to distinguish the different agents involved. Ultrastructural observations on Mikrocytos roughleyi revealed similarities with Bonamia spp., particularly in regard to the presence of electron-dense haplosporosomes and mitochondria, whose absence from M mackini also indicate that M roughleyi and M mackini are ...


Dissolved Organic Nitrogen: A Dynamic Participant In Aquatic Ecosystems, T Berman, Da Bronk Apr 2003

Dissolved Organic Nitrogen: A Dynamic Participant In Aquatic Ecosystems, T Berman, Da Bronk

VIMS Articles

In both marine and freshwaters, the concentration of dissolved organic nitrogen (DON) frequently exceeds that of dissolved inorganic nitrogen (DIN), including ammonium, nitrate, and nitrite. Recent evidence indicates that many organic N compounds are released into the DON pool and taken up from this pool by planktonic microbiota on timescales of hours to days. This observation suggests that many components of the DON pool can play an active role in supplying N nutrition directly or indirectly to phytoplankton and bacteria and, in so doing, may affect the species composition of the ambient microbial assemblage. Here we present an overview of ...


Molecular Detection Of The Oyster Parasite Mikrocytos Mackini, And A Preliminary Phylogenetic Analysis, Ryan Carnegie, Gr Meyer, Et Al Apr 2003

Molecular Detection Of The Oyster Parasite Mikrocytos Mackini, And A Preliminary Phylogenetic Analysis, Ryan Carnegie, Gr Meyer, Et Al

VIMS Articles

The protistan parasite Mikrocytos mackini, the causative agent of Denman Island disease in the oyster Crassostrea gigas in British Columbia, Canada, is of wide concern because it can infect other oyster species and because its life cycle, mode of transmission, and origins are unknown. PCR and fluorescent in situ hybridization (FISH) assays were developed for M mackini, the PCR assay was validated against standard histopathological diagnosis, and a preliminary phylogenetic analysis of the M mackini small-subunit ribosomal RNA gene (SSU rDNA) was undertaken. A PCR designed specifically not to amplify host DNA generated a 544 bp SSU rDNA fragment from ...


Abundance And Exploitation Rate Of The Blue Crab (Callinectes Sapidus) In Chesapeake Bay, Af Sharov, Jh Volstad, Gr Davis, Bk Davis, Rom Lipcius, Mm Montane Mar 2003

Abundance And Exploitation Rate Of The Blue Crab (Callinectes Sapidus) In Chesapeake Bay, Af Sharov, Jh Volstad, Gr Davis, Bk Davis, Rom Lipcius, Mm Montane

VIMS Articles

We estimated absolute abundance of the blue crab stock in Chesapeake Bay during winter from stratified random surveys conducted baywide from 1990 to 1999, using the swept-area method. We estimated catching efficiency of the survey gear from multiple depletion experiments to correct for temporal and vessel/area differences in catchability. The survey was conducted during the winter, when crabs are dormant and "buried" in the bottom. Analysis of crab carapace width (CW) frequency distributions revealed two size modes: CW less or equal 60 mm and CW greater than 60 mm, corresponding to age-0 (recruits) and age-1+ (one year and older ...


Aspects Of The Pathophysiology Of Blue Crabs, Callinectes Sapidus, Infected With The Parasitic Dinoflagellate Hematodinium Perezi, Jeffrey D. Shields, C Scanlon, A Volety Mar 2003

Aspects Of The Pathophysiology Of Blue Crabs, Callinectes Sapidus, Infected With The Parasitic Dinoflagellate Hematodinium Perezi, Jeffrey D. Shields, C Scanlon, A Volety

VIMS Articles

Blue crabs, Callinectes sapidus, infected with Hematodinium perezi frequently show signs of weakness and lethargy and die when stressed by handling or capture. Radical changes to the hemolymph of heavily infected crabs are obvious by reduced clotting ability, discoloration. and a 50% to 70% decline in total hemocyte density. Few other signs of infection are associated with infections and the resulting mortalities of blue crabs. To assay physiological changes in infected crabs, we measured serum proteins, hemocyanin, serum acid phosphatase, various hemolymph enzymes, hernagglutination activity, and tissue glycogen levels in relation to intensity of infection with H. perezi. Serum proteins ...


Summary Of Session: Ecology Of Early Benthic Juveniles, Rom Lipcius Mar 2003

Summary Of Session: Ecology Of Early Benthic Juveniles, Rom Lipcius

VIMS Articles

The unifying theme of the presentations in the session on the ecology of early benthic juveniles reflected a general research thrust in marine ecology and a major emphasis in blue crab ecology, specifically that the roles of dispersal and mortality in determining habitat-specific distribution patterns of young juveniles remain largely unknown. As a consequence, presentations on the ecology of postlarvae and early benthic juveniles focused on four major processes—recruitment, predation, movements, and habitat relationships, with most of the presentations integrating two or more of these processes. Two of the presentations examined recruitment and habitat relationships of young juveniles (Spitzer ...


Evidence For Sperm Limitation In The Blue Crab, Callinectes Sapidus, Ah Hines, Pr Jivoff, Pj Bushmann, J Van Montfrans, Et Al Mar 2003

Evidence For Sperm Limitation In The Blue Crab, Callinectes Sapidus, Ah Hines, Pr Jivoff, Pj Bushmann, J Van Montfrans, Et Al

VIMS Articles

Reproductive success of female blue crabs may be limited by the amount of sperm received during the female's single, lifetime mating. Sperm must be stored in seminal receptacles until eggs are produced and fertilized months to years after mating. Further, intense fishing pressure impacts male abundance, male size and population sex ratio, which affect ejaculate quantity. We measured temporal variation in seminal receptacle contents in relation to brood production for two stocks differing in both fishing pressure on males and latitudinal effects on reproductive season: Chesapeake Bay, Maryland and Virginia, experienced intensive fishing and relatively short reproductive season; and ...


Mycobacterium Shottsii Sp Nov., A Slowly Growing Species Isolated From Chesapeake Bay Striped Bass (Morone Saxatilis), Mw Rhodes, H Kator, S Kotob, P Van Berkum, I Kaattari, Wolfgang K. Vogelbein, Et Al Mar 2003

Mycobacterium Shottsii Sp Nov., A Slowly Growing Species Isolated From Chesapeake Bay Striped Bass (Morone Saxatilis), Mw Rhodes, H Kator, S Kotob, P Van Berkum, I Kaattari, Wolfgang K. Vogelbein, Et Al

VIMS Articles

Slowly growing, non-pigmented mycobacteria were isolated from striped bass (Morone saxatilis) during an epizootic of mycobacteriosis in the Chesapeake Bay. Growth characteristics, acid-fastness and results of 16S rRNA gene sequencing were consistent with those of the genus Mycobacterium. A unique profile of biochemical reactions was observed among the 21 isolates. A single cluster of eight peaks identified by analysis of mycolic acids (HPLC) resembled those of reference patterns but differed in peak elution times from profiles of reference species of the Mycobacterium tuberculosis complex. One isolate (M175(T)) was placed within the slowly growing mycobacteria by analysis of aligned 16S ...


Research Priorities For Diseases Of The Blue Crab Callinectes Sapidus, Jeffrey D. Shields Mar 2003

Research Priorities For Diseases Of The Blue Crab Callinectes Sapidus, Jeffrey D. Shields

VIMS Articles

The diseases of blue crabs have received relatively little attention compared to those of the American oyster, Crassostrea virginica, or the penaeid shrimps, Penaeus spp. This is primarily due to differences in resource management (fishery vs. aquaculture), and the magnitude of financial losses suffered by the industries from protozoal diseases in oysters and viral diseases in shrimp, respectively. Nonetheless, several agents including Vibrio spp., Hematodinium perezi, Paramoeba perniciosa, Ameson michaelis and Loxothylacus texanus are highly pathogenic in blue crabs, and have the capacity to severely damage certain segments of the crab population. This paper is meant to highlight priorities for ...


Bioenergetic Modeling Of The Blue Crab (Callinectes Sapidus) Using The Fish Bioenergetics (3.0) Computer Program, Bj Brylawski, Tj Miller Mar 2003

Bioenergetic Modeling Of The Blue Crab (Callinectes Sapidus) Using The Fish Bioenergetics (3.0) Computer Program, Bj Brylawski, Tj Miller

VIMS Articles

To understand better the ecology and growth dynamics of the blue crab (Callinectes sapidus). we developed a bioenergetic model based upon the Fish Bioenergetics 3.0 computer program. We summarized and analyzed existing data from published studies on the ecology and physiology of both blue crab and closely related species to parameterize the model. The respiration and excretion components were estimated directly from published studies. Parts of the consumption component were estimated indirectly. The resulting model was evaluated for applicability against known growth trajectories from field and laboratory studies. The model predicted observed growth and consumption to a first approximation ...


Potential Bottom-Up Control Of Blue Crab Distribution At Various Spatial Scales, Rd Seitz, Rom Lipcius, Wt Stockhausen, Et Al Mar 2003

Potential Bottom-Up Control Of Blue Crab Distribution At Various Spatial Scales, Rd Seitz, Rom Lipcius, Wt Stockhausen, Et Al

VIMS Articles

Top-down (i.e., predation), bottom-up (i.e., food availability), and physical factors may influence blue crab (Callinectes sapidus) distribution. To assess the role of bottom-up and physical process in blue crab distributions, we concurrently measured density of the blue crab (Callinectes sapidus), density of its principal prey, the Baltic clam (Macoma balthica), and physical characteristics in mud and sand habitats spanning various spatial scales (1-10 km and 10-50 km) in the York River, Chesapeake Bay. Clam and crab densities were intermediate in mud, low in downriver sand, and high in upriver sand. Clam and crab densities were not correlated in ...


Spatial Dynamics And Value Of A Marine Protected Area And Corridor For The Blue Crab Spawning Stock In Chesapeake Bay, Rom Lipcius, Wt Stockhausen, Rd Seitz, Pj Geer Mar 2003

Spatial Dynamics And Value Of A Marine Protected Area And Corridor For The Blue Crab Spawning Stock In Chesapeake Bay, Rom Lipcius, Wt Stockhausen, Rd Seitz, Pj Geer

VIMS Articles

In lower Chesapeake Bay, a 172,235 ha marine protected area and corridor (MPAC) was recently established to protect blue crab adult females either en route to or at the spawning grounds during the reproductive period. The MPAC was justified due to a recent substantial decline in spawning stock biomass. It was situated in waters deeper than 10 in throughout the lower bay due to the high abundances of adult females in this zone, and it was an expansion of a historical spawning sanctuary near the bay mouth to include northward extensions (upper and lower MPACs). We examined spatial dynamics ...


Simulated Effects Of Seagrass Loss And Restoration On Settlement And Recruitment Of Blue Crab Postlarvae And Juveniles In The York River, Chesapeake Bay, Wt Stockhausen, Rom Lipcius Mar 2003

Simulated Effects Of Seagrass Loss And Restoration On Settlement And Recruitment Of Blue Crab Postlarvae And Juveniles In The York River, Chesapeake Bay, Wt Stockhausen, Rom Lipcius

VIMS Articles

Seagrass meadows provide important settlement habitat, food and refuge for postlarvae and young juveniles of the blue crab, Callinectes sapidus. In the York River, Chesapeake Bay, area] cover and distribution of seagrass beds has declined historically. Beds which existed 12-25 km upriver from the mouth disappeared and have not recovered. A model for planktonic postlarval behavior, coupled with a 3-dimensional hydrodynamic transport model for the York River, was used to investigate potential effects of the decline in seagrass abundance, and hypothetical restoration, on blue crab settlement and recruitment to the benthos, both in seagrass and to unvegetated bottom. Effects of ...


Partitioning Loss Rates Of Early Juvenile Blue Crabs From Seagrass Habitats Into Mortality And Emigration, Ll Etherington, Db Eggleston, Wt Stockhausen Mar 2003

Partitioning Loss Rates Of Early Juvenile Blue Crabs From Seagrass Habitats Into Mortality And Emigration, Ll Etherington, Db Eggleston, Wt Stockhausen

VIMS Articles

Determining how post-settlement processes modify patterns of settlement is vital in understanding the spatial and temporal patterns of recruitment variability of species with open populations. Generally, either single components of post-settlement loss (mortality or emigration) are examined at a time, or else the total loss is examined without discrimination of mortality and emigration components. The role of mortality in the loss of early juvenile blue crabs, Callinectes sapidus, has been addressed in a few studies; however, the relative contribution of emigration has received little attention. We conducted mark-recapture experiments to examine the relative contribution of mortality and emigration to total ...


Experimental Mycobacteriosis In Striped Bass Morone Saxatilis, Dt Gauthier, Mw Rhodes, Wolfgang K. Vogelbein, H Kator, Ca Ottinger Mar 2003

Experimental Mycobacteriosis In Striped Bass Morone Saxatilis, Dt Gauthier, Mw Rhodes, Wolfgang K. Vogelbein, H Kator, Ca Ottinger

VIMS Articles

Striped bass Morone saxatilis were infected intraperitoneally with approximately 10(5) Mycobacterium marinum, M. shottsii sp. nov., or M. gordonae. Infected fish were maintained in a flow-through freshwater system at 18 to 21degreesC, and were examined histologically and bacteriologically at 2, 4, 6, 8, 17, 26, 36 and 45 wk post-infection (p.i.). M. marinum caused acute peritonitis, followed by extensive granuloma development in the mesenteries, spleen and anterior kidney. Granulomas in these tissues underwent a temporal progression of distinct morphological stages, culminating in well-circumscribed lesions surrounded by normal or healing tissue. Mycobacteria were cultured in high numbers from splenic ...


Trophic Uptake And Transfer Of Dmsp In Simple Planktonic Food Chains, Kw Tang, R Simo Mar 2003

Trophic Uptake And Transfer Of Dmsp In Simple Planktonic Food Chains, Kw Tang, R Simo

VIMS Articles

Recent field studies suggest that a large portion of phytoplankton-DMSP could be lost to grazing by protozoans, but the fate of the grazed DMSP remains uncertain. In the laboratory we studied trophic uptake and transfer of phytoplankton-DMSP through simple planktonic food chains using 2 experimental approaches: (1) A direct approach measured the ingestion and retention of phytoplankton-DMSP by the heterotrophic dinoflagellate Gyrodinium dominans. Overall, DMSP content of G. dominans estimated by the direct approach was highly variable, likely because of the low G. dominans biomass relative to phytoplankton in the samples. (2) An indirect approach, in which the omnivorous copepod ...


Infectivity And Pathogenicity Of The Oomycete Aphanomyces Invadans In Atlantic Menhaden Brevoortia Tyrannus, Y Kiryu, Jeffrey D. Shields, Wolfgang K. Vogelbein, H Kator, Vs Blazer Mar 2003

Infectivity And Pathogenicity Of The Oomycete Aphanomyces Invadans In Atlantic Menhaden Brevoortia Tyrannus, Y Kiryu, Jeffrey D. Shields, Wolfgang K. Vogelbein, H Kator, Vs Blazer

VIMS Articles

Atlantic menhaden Brevoortia tyrannus develop characteristic skin ulcers in response to infection by the oomycete Aphanomyces invadans. To investigate pathogenicity, we conducted a dose response study. Juvenile menhaden were inoculated subcutaneously with 0, 1, 5, 10, 100, and 500 secondary zoospores per fish and monitored for 37 d post-injection (p.i.). Survival rates declined with increasing zoospore dose, with significantly different survivorship curves for the different doses. Moribund and dead fish exhibited characteristic ulcerous lesions at the injection site starting at 13 d p.i. None of the sham-injected control fish (0 zoospore treatment) died. The LD50 (lethal dose killing ...


Salinity Tolerance Of Larval Rapana Venosa: Implications For Dispersal And Establishment Of An Invading Predatory Gastropod On The North American Atlantic Coast, Roger L. Mann, Juliana M. Harding Feb 2003

Salinity Tolerance Of Larval Rapana Venosa: Implications For Dispersal And Establishment Of An Invading Predatory Gastropod On The North American Atlantic Coast, Roger L. Mann, Juliana M. Harding

VIMS Articles

The lack of quantitative data on the environmental tolerances of the early life-history stages of invading species hinders estimation of their dispersal rates and establishment ranges in receptor environments. We present data on salinity tolerance for all stages of the ontogenetic larval development of the invading predatory gastropod Rapana venosa, and we propose that salinity tolerance is the dominant response controlling the potential dispersal ( = invasion) range of the species into the estuaries of the Atlantic coast of the United States from the current invading epicenter in the southern Chesapeake Bay. All larval stages exhibit 48-h tolerance to salinities as low ...


Bacterioplankton Dynamics In The York River Estuary: Primary Influence Of Temperature And Freshwater Inputs, G. E. Schultz, E. D. White, H. W. Ducklow Jan 2003

Bacterioplankton Dynamics In The York River Estuary: Primary Influence Of Temperature And Freshwater Inputs, G. E. Schultz, E. D. White, H. W. Ducklow

VIMS Articles

Bacterial community dynamics were investigated over seasonal and basin scales within the York River estuary, Virginia. Variables describing bacterioplankton dynamics were measured at 6 stations spanning the entire salinity gradient (0 to ca. 20 psu over 60 km). Samples were collected monthly from June 1996 through May 1997 and every other month from June 1997 through May 1998. Bacterial abundance and production were high throughout the estuary. Bacterial abundance ranged from 4.4 x 10(8) to 1.3 x 10(10) cells l(-1). Incorporation of (3)H-thymidine ranged from 10 to 863 pmol(-1) h(-1) while (3 ...


Perkinsus Sp Infection Risk For Manila Clams, Venerupis Philippinarum (A. Adams And Reeve, 1850) On The Pacific Coast Of North And Central America, Ra Elston, Cf Dungan, Tr Meyers, Kimberly S. Reece Jan 2003

Perkinsus Sp Infection Risk For Manila Clams, Venerupis Philippinarum (A. Adams And Reeve, 1850) On The Pacific Coast Of North And Central America, Ra Elston, Cf Dungan, Tr Meyers, Kimberly S. Reece

VIMS Articles

Manila clams (Venerupis philippinarum, A. Adams and Reeve 1850) are an important aquaculture species on the west coast of North America and are also cultured in Europe, Asia, and other locations. Clams cultured on the west coast of North America are free of Perkinsus sp. infections, while clams from certain Asian and European sources are infected. Infection in Korean Manila clams is reportedly associated with high morbidity and mortality. We evaluated the health status of readily accessible Manila clam juveniles from Korea that were proposed for importation into Mexican waters where they would increase in size, and then be shipped ...