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VIMS Articles

2005

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Articles 1 - 28 of 28

Full-Text Articles in Life Sciences

Revision Of The Genus Bdellamaris (Hirudinea : Piscicolidae) Including A New Combination, Bdellamaris Manteri, J Williams, E Burreson Dec 2005

Revision Of The Genus Bdellamaris (Hirudinea : Piscicolidae) Including A New Combination, Bdellamaris Manteri, J Williams, E Burreson

VIMS Articles

The New Zealand fish leech genus Bdellamaris was revised and a redescription of the type species, Bdellamaris eptatreti, was made using material from Eptatretus cirrhatus, the type host for B. eptatreti. Since the holotype has been lost and paratypes exist only in the form. of frontal sections of approximately one third of a leech, a neotype was designated. Individuals in Bdellamaris lack eyes, ocelli, and conducting tissue and possess 11 pairs of pulsatile vesicles, 6 pairs of testisacs, accessory gland cells on the terminal portion of the male reproductive system, and a seminal receptacle. Bdellamaris eptatreti is characterised by a ...


Comparative Analysis Of Mycobacterial Infections In Wild Striped Bass Morone Saxatilis From Chesapeake Bay, Im Kaattari, Mw Rhodes, H Kator, Sl Kaattari Nov 2005

Comparative Analysis Of Mycobacterial Infections In Wild Striped Bass Morone Saxatilis From Chesapeake Bay, Im Kaattari, Mw Rhodes, H Kator, Sl Kaattari

VIMS Articles

During an ongoing epizootic of mycobacteriosis, wild striped bass Morone saxatilis from Chesapeake Bay were analyzed using 3 methods for detection of either mycobacterial infection or associated granulomatous pathology. The specific detection techniques, which utilized aseptically collected splenic tissue, were histology, quantitative culture and nested PCR. Based on analysis of 118 samples, detection of infection differed significantly between the 3 methods (chi-square, p = 0.0007). Quantitative culture and nested PCR detected similar, higher rates of infection (69 and 75%, respectively) than the histological method (52%). Although primary PCR assays for a 924 to 940 bp segment of the mycobacterial 16S ...


Effects Of Triclosan On Growth, Viability And Fatty Acid Synthesis Of The Oyster Protozoan Parasite Perkinsus Marinus, Em Lund, P Soudant, Fle Chu, E Harvey, S Bolton, A Flowers Nov 2005

Effects Of Triclosan On Growth, Viability And Fatty Acid Synthesis Of The Oyster Protozoan Parasite Perkinsus Marinus, Em Lund, P Soudant, Fle Chu, E Harvey, S Bolton, A Flowers

VIMS Articles

Perkinsus marinus, a protozoan parasite of the Eastern oyster Crassostrea virginica, has severely impacted oyster populations from the Mid-Atlantic region to the Gulf of Mexico coast of North America for more than 30 yr. Although a chemotherapeutic treatment to reduce or eliminate P. marinus from infected oysters would be useful for research and hatchery operations, an effective and practical drug treatment does not currently exist. In this study, the antimicrobial drug triclosan 5-chloro-2-(2,4 dichlorophenoxy) phenol, a specific inhibitor of Fab1 (enoyl-acyl-carrier-protein reductase), an enzyme in the Type 11 class of fatty acid synthetases, was tested for its effects ...


Identification And Partial Characterisation Of Metalloproteases Secreted By A Mesanophrys-Like Ciliate Parasite Of The Norway Lobster Nephrops Norvegicus, Hamish J. Small, Dm Neil, Et Al Oct 2005

Identification And Partial Characterisation Of Metalloproteases Secreted By A Mesanophrys-Like Ciliate Parasite Of The Norway Lobster Nephrops Norvegicus, Hamish J. Small, Dm Neil, Et Al

VIMS Articles

A ciliate parasite, tentatively identified as Mesanophrys sp. of Norway lobsters Nephrops norvegicus, is demonstrated to secrete several proteases into the culture medium (modified Nephrops saline). Analyses using substrate-impregnated sodium dodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE) revealed 12 activity bands differing greatly in mobility in the gels. The complete inhibition of proteolytic activity by 1,10-phenanthroline indicated that the proteases are of the metallo class. The proteases were active at the physiological temperature (8 degrees C) and haemolymph pH (7.8) of the host. The proteases were selective in the degradation of several host proteins, including the myosin heavy chain, which is ...


Viable Gut Passage Of Cyanobacteria Through The Filter-Feeding Fish Atlantic Menhaden, Brevoortia Tyrannus, Kd Friedland, Dw Ahrenholz, Lw Haas Jul 2005

Viable Gut Passage Of Cyanobacteria Through The Filter-Feeding Fish Atlantic Menhaden, Brevoortia Tyrannus, Kd Friedland, Dw Ahrenholz, Lw Haas

VIMS Articles

We examined the contents of the alimentary tract of juvenile Atlantic menhaden, an obligate filter-feeding fish, with epifluoresence microscopy. All plankton taxa and detrital material observed in plankton samples from the sampling area could also be found in the esophagus of the fish. The corresponding plankton taxa were absent from the pre-feces sampled in the hindgut with the exception of cyanobacteria, which were found intact and fluorescing as they do in nature. The survival of cyanobacteria during gut passage and their presence in menhaden feces may enhance both nutrient availability and the delivery of these cells to the benthos. Additionally ...


Effects Of Sunlight On Decomposition Of Estuarine Dissolved Organic C, N And P And Bacterial Metabolism, Sl Mccallister, Je Bauer, J Kelly, Hw Ducklow Jul 2005

Effects Of Sunlight On Decomposition Of Estuarine Dissolved Organic C, N And P And Bacterial Metabolism, Sl Mccallister, Je Bauer, J Kelly, Hw Ducklow

VIMS Articles

The effects of natural sunlight and microbial decomposition on DOC, DON, and DOP were investigated along the salinity gradient of a temperate coastal plain estuary. The impact of sunlight-irradiated DOM on bacterial properties (bacterial abundance, production, bacterial growth efficiency [BGE]) was also followed. Surface-water light levels resulted in no detectable abiotic production of NH4+ or PO43- or loss of DOC. Bacterial decomposition of DOC was enhanced by 27 to 200 % in irradiated relative to dark treatments. There was, however, no corresponding enhancement in DON and DOP remineralization. Significant differences in bacterial decomposition of light-exposed DOC were frequently observed following prolonged ...


A Review Of The Parasitic Dinoflagellates Hematodinium Species And Hematodinium-Like Infections In Marine Crustaceans, Gd Stentiford, Jeffrey D. Shields Jul 2005

A Review Of The Parasitic Dinoflagellates Hematodinium Species And Hematodinium-Like Infections In Marine Crustaceans, Gd Stentiford, Jeffrey D. Shields

VIMS Articles

Parasitic dinoflagellates in the genus Hematodinium are important parasites of marine Crustacea. Outbreaks of these parasites have damaged commercial stocks of Norway lobster Nephrops norvegicus, snow crab Chionoecetes opilio, Tanner crab C. bairdi, American blue crab Callinectes sapidus, and velvet swimming crab Necora puber. Species of Hematodinium can reach high enough levels to regulate their host populations, but mortalities are also centred on the unfished juveniles and females, hosts not normally sampled by fisheries; hence impacts are often underreported. Seasonal prevalences of up to 85 % occur annually in many host populations; in effect, these parasites form cryptic blooms in the ...


Mycobacterium Pseudoshottsii Sp Nov., A Slowly Growing Chromogenic Species Isolated From Chesapeake Bay Striped Bass (Morone Saxatilis), Mw Rhodes, H Kator, Et Al, I Kaattari, Kimberly S. Reece, Wolfgang K. Vogelbein, Ca Ottinger May 2005

Mycobacterium Pseudoshottsii Sp Nov., A Slowly Growing Chromogenic Species Isolated From Chesapeake Bay Striped Bass (Morone Saxatilis), Mw Rhodes, H Kator, Et Al, I Kaattari, Kimberly S. Reece, Wolfgang K. Vogelbein, Ca Ottinger

VIMS Articles

A group of slowly growing photochromogenic mycobacteria was isolated from Chesapeake Bay striped bass (Morone saxatilis) during an epizootic of mycobacteriosis. Growth characteristics, acid-fastness and 16S rRNA gene sequencing results were consistent with those of the genus Mycobacterium, Biochemical reactions, growth characteristics and mycolic acid profiles (HPLC) resembled those of Mycobacterium shottsii, a non-pigmented mycobacterium also isolated during the same epizootic. Sequencing of the 16S rRNA genes, the gene encoding the exported repeated protein (erp) and the gene encoding the 65 kDa heat-shock protein (hsp65) and restriction enzyme analysis of the hsp65 gene demonstrated that this group of isolates is ...


Epidemiology Of Bitter Crab Disease (Hematodinium Sp.) In Snow Crabs Chionoecetes Opilio From Newfoundland, Canada, Jeffrey D. Shields, Dm Taylor, Et Al May 2005

Epidemiology Of Bitter Crab Disease (Hematodinium Sp.) In Snow Crabs Chionoecetes Opilio From Newfoundland, Canada, Jeffrey D. Shields, Dm Taylor, Et Al

VIMS Articles

The parasitic dinoflagellate Hematodinium sp. causes a condition known as bitter crab disease (BCD) in snow crabs Chionoecetes opilio and Tanner crabs C. bairdi. As the name of the condition implies, crabs infected with BCD are unmarketable due to their bitter flavor. We surveyed the distribution of BCD in 3 regions within the snow crab fishery of Newfoundland from 1997 to 2003. Over time, the disease has become firmly established in Conception and Bonavista Bays and persists at low levels on the Avalon fishing grounds. An epizootic occurred within Bonavista and Conception Bays in 1999 and persisted in Conception Bay ...


Veined Rapa Whelk (Rapana Venosa) Range Extensions In The Virginia Waters Of Chesapeake Bay, Usa, Jm Harding, Roger L. Mann Jan 2005

Veined Rapa Whelk (Rapana Venosa) Range Extensions In The Virginia Waters Of Chesapeake Bay, Usa, Jm Harding, Roger L. Mann

VIMS Articles

Three recent range extensions for the Chesapeake Bay, Virginia, veined rapa whelk (Rapana venosa) population are described. These extensions into Tangier Sound, the mid James River estuary, and to Cape Henry at the Bay mouth extend respectively, the northern, western, and southeastern boundaries of the occupied rapa whelk range in Virginia waters. Salinity and tidal circulation mediate the distribution of adults and larvae of this animal. During dry years (e.g., 2001 and 2002) adult rapa whelks may move up-estuary in western tributaries like the James River, given increased salinity and available habitat and food resources. Declines in salinities (or ...


The Case For Sequencing The Pacific Oyster Genome, D Hedgecock, Pm Gaffney, P Goulletquer, Xm Guo, Kimberly S. Reece, G. Warr Jan 2005

The Case For Sequencing The Pacific Oyster Genome, D Hedgecock, Pm Gaffney, P Goulletquer, Xm Guo, Kimberly S. Reece, G. Warr

VIMS Articles

An international community of biologists presents the Pacific oyster Crassostrea gigas as a candidate for genome sequencing. This oyster has global distribution and for the past several years the highest annual production of any freshwater or marine organism (4.2 million metric tons, worth $3.5 billion US). Economic and cultural importance of oysters motivates a great deal of biologic research, which provides a compelling rationale for sequencing an oyster genome. Strong rationales for sequencing the oyster genome also come from contrasts to other genomes: membership in the Lophotrochozoa, an understudied branch of the Eukaryotes and high fecundity, with concomitantly ...


Evidence Of Recent Recruitment In The Ocean Quahog Arctica Islandica In The Mid-Atlantic Bight, En Powell, Roger L. Mann Jan 2005

Evidence Of Recent Recruitment In The Ocean Quahog Arctica Islandica In The Mid-Atlantic Bight, En Powell, Roger L. Mann

VIMS Articles

We report results of a survey explicitly focused on ocean quahog recruitment in the Mid-Atlantic Bight. The recruitment survey resampled all NMFS survey sites south of Hudson Canyon and a selection of sites north and east of Hudson Canyon off the Long Island coast over the entire depth range of this species with the exception of the most inshore reaches off Long Island. More ocean quahogs were encountered, on a per tow basis, in the vicinity of and north of Hudson Canyon. The proportion of recruits in the size-frequency distribution was higher in the south and the most recent recruitment ...


Application Of Pop-Up Satellite Archival Tag Technology To Estimate Postrelease Survival Of White Marlin (Tetrapturus Albidus) Caught On Circle And Straight-Shank ("J") Hooks In The Western North Atlantic Recreational Fishery, Az Horodysky, John Graves Jan 2005

Application Of Pop-Up Satellite Archival Tag Technology To Estimate Postrelease Survival Of White Marlin (Tetrapturus Albidus) Caught On Circle And Straight-Shank ("J") Hooks In The Western North Atlantic Recreational Fishery, Az Horodysky, John Graves

VIMS Articles

Short-duration (5- or 10-day) deployments of pop-up satellite archival tags were used to estimate survival of white marlin (Tetrapturus albidus) released from the western North Atlantic recreational fishery. Forty-one tags, each recording temperature, pressure, and light level readings approximately every two minutes for 5-day tags (n=5) or four minutes for 10-day tags (n=36), were attached to white marlin caught with dead baits rigged on straight-shank ("J") hooks (n=21) or circle hooks (n = 20) in offshore waters of the U.S. Mid-Atlantic region, the Dominican Republic, Mexico, and Venezuela. Forty tags (97.8%) transmitted data to the satellites ...


Disappearance Of The Natural Emergent 3-Dimensional Oyster Reef System Of The James River, Virginia, 1871-1948, H Woods, Wj Hargis Jr., Carl Hershner, Pamela Mason Jan 2005

Disappearance Of The Natural Emergent 3-Dimensional Oyster Reef System Of The James River, Virginia, 1871-1948, H Woods, Wj Hargis Jr., Carl Hershner, Pamela Mason

VIMS Articles

Anecdotal reports have long indicated that oysters, Crassostrea virginica (Gmelin), in the Chesapeake Bay once grew in large 3-dimensional reef structures. However, hard evidence of widespread 3-dimensional oyster reefs in the Chesapeake Bay has been scarce. This study uses data collected from historic charts of the James River, one of the most productive oyster producing tributaries of the Chesapeake Bay, to examine the natural occurrence of these reefs as well as their destruction. An early series of charts from the 1870s clearly documents widespread emergent oyster reefs in the James River from Burwell's Bay to Newport News Point. They ...


Seasonal Variation Of Heat Shock Protein 70 In Eastern Oysters (Crassostrea Virginica) Infected With Perkinsus Marinus (Dermo), Vg Encomio, Fle Chu Jan 2005

Seasonal Variation Of Heat Shock Protein 70 In Eastern Oysters (Crassostrea Virginica) Infected With Perkinsus Marinus (Dermo), Vg Encomio, Fle Chu

VIMS Articles

Eastern oysters (Crassostrea virginica) inhabit highly variable environments and are exposed to large seasonal shifts in temperature. Prevalence and intensity of oyster diseases, particularly Perkinsus marinas (Dermo), increase during thermally stressful periods, thus posing additional stress on the oyster host. Heat shock proteins (hsps) are important in protecting organisms from thermal and overall environmental stress. Additionally, hsps may play protective roles for both the host and parasite during infection. The interactive effects of temperature and disease on heat shock protein expression in oysters, however, are unknown. In this study, using slot and western blotting assays, seasonal and intraspecific variation in ...


Comparison Of Two Approaches For Estimating Natural Mortality Based On Longevity, David A. Hewitt, John M. Hoenig Jan 2005

Comparison Of Two Approaches For Estimating Natural Mortality Based On Longevity, David A. Hewitt, John M. Hoenig

VIMS Articles

No abstract provided.


Quantification Of Drag And Lift Imposed By Pop-Up Satellite Archival Tags And Estimation Of The Metabolic Cost To Cownose Rays (Rhinoptera Bonasus), Donna S. Grusha, Mark R. Patterson Jan 2005

Quantification Of Drag And Lift Imposed By Pop-Up Satellite Archival Tags And Estimation Of The Metabolic Cost To Cownose Rays (Rhinoptera Bonasus), Donna S. Grusha, Mark R. Patterson

VIMS Articles

The recent development of the p)p-up satellite archival tag (PSAT) has allowed the collection of information on a tagged animal, such as geolocation, pressure (depth), and ambient water temperature. The success of early studies, where PSATs were used on pelagic fishes, has spurred increasing interest in the use of these tags on a large variety of species and age groups. However, some species and age groups may not be suitable candidates for carrying a PSAT because of the relatively large size of the tag and the consequent energy cost to the study animal. We examined potential energetic costs to ...


Effects Of Physical Fragmentation On Remineralization Of Marine Snow, Sa Goldthwait, Ca Carlson, Gk Henderson, Al Alldredge Jan 2005

Effects Of Physical Fragmentation On Remineralization Of Marine Snow, Sa Goldthwait, Ca Carlson, Gk Henderson, Al Alldredge

VIMS Articles

The vast majority of carbon lost from ocean surface waters sinks as large, relatively rare, marine snow and fecal pellets. Fragmentation of these particles into more slowly sinking daughter particles has been proposed previously to partly explain the rapid loss of sinking carbon below the mixed layer. In this study we investigated 2 other less obvious potential consequences of aggregate disruption, namely the release of dissolved interstitial compounds upon fragmentation and accelerated degradation due to increased particle surface area. We found that upon fragmentation natural marine aggregates, ranging in size from 3 to 6 mm diameter, released dissolved organic carbon ...


Copepods As Microbial Hotspots In The Ocean: Effects Of Host Feeding Activities On Attached Bacteria, Kw Tang Jan 2005

Copepods As Microbial Hotspots In The Ocean: Effects Of Host Feeding Activities On Attached Bacteria, Kw Tang

VIMS Articles

Through ingestion a copepod introduces rich organic substrates into its guts and fecal pellets, where dense bacteria may exploit them and show fast growth. Thus, a copepod and its fecal pellets may be regarded as microbial hotspots in the ocean. This study investigated the effects of copepods' feeding activities on the associated bacteria, using the Most Probable Number (MPN) method. Starved Acartia tonsa (calanoid copepod) carried a background bacteria population of 103 to 10(4) copepod(-1). When fed axenic cultures of algae Rhodomonas salina or Dunaliella tertiolecta, the bacterial abundance increased curvilinearly with the copepods' ingestion rates. When fed ...


Herpes Virus In Juvenile Pacific Oysters Crassostrea Gigas From Tomales Bay, California, Coincides With Summer Mortality Episodes, Cs Friedman, Rm Estes, Na Stokes, Ca Burge, Js Hargove, Bj Barber, Ra Elston, Em Burreson, Kimberly S. Reece Jan 2005

Herpes Virus In Juvenile Pacific Oysters Crassostrea Gigas From Tomales Bay, California, Coincides With Summer Mortality Episodes, Cs Friedman, Rm Estes, Na Stokes, Ca Burge, Js Hargove, Bj Barber, Ra Elston, Em Burreson, Kimberly S. Reece

VIMS Articles

Pacific Crassostrea gigas and eastern C. virginica oysters were examined between June 2002 and April 2003 from 8 locations along the east, west and south USA coasts for oyster herpes virus (OsHV) infections using the A primer set in a previously developed PCR test. Only surviving Pacific oysters from a mortality event in Tomales Bay, California, USA, where annual losses of oysters have occurred each summer since 1993, were infected with a herpes-like virus in 2002. PCR examination using template amounts of both 50 and 500 ng were essential for OsHV detection. Sequence analysis indicated that the Tomales Bay OsHV ...


Calculating Highly Fluctuated Suspended Sediment Fluxes From Mountainous Rivers In Taiwan, Shuh-Ji Kao, Tsung-Yu Lee, J. D. Milliman Jan 2005

Calculating Highly Fluctuated Suspended Sediment Fluxes From Mountainous Rivers In Taiwan, Shuh-Ji Kao, Tsung-Yu Lee, J. D. Milliman

VIMS Articles

Small drainage basins, highly fractured rock, high relief, and steep gradients make Taiwan watersheds particularly sensitive to episodic events such as typhoons and earthquakes, and to various types of anthropogenic disturbance. Here we analyze the characteristics of a long-term hydrological dataset from Taiwan and re-evaluate methods used to calculate sediment loads for Taiwan's event-driven rivers. We suggest using the rating curve method stratified down to seasonal levels to reflect the rapid changes in the relationship between water discharge and suspended sediment load. A program is developed to determine the optimal time-interval for constructing rating curves, and is used to ...


Food Color And Marine Turtle Feeding Behavior: Can Blue Bait Reduce Turtle Bycatch In Commercial Fisheries?, Y Swimmer, R Arauz, B Higgins, L Mcnaughton, M. Mccracken, J. Ballestero, Richard Brill Jan 2005

Food Color And Marine Turtle Feeding Behavior: Can Blue Bait Reduce Turtle Bycatch In Commercial Fisheries?, Y Swimmer, R Arauz, B Higgins, L Mcnaughton, M. Mccracken, J. Ballestero, Richard Brill

VIMS Articles

We conducted laboratory and field experiments to investigate the behavioral responses of Kemp's ridley Lepidochelys kempii and loggerhead turtles Caretta caretta to whole squid dyed different colors. Our ultimate goal was to identify bait modifications that could reduce the interaction of turtles with longline fishing gear. In captivity, both turtle species clearly preferred untreated squid over squid that had been dyed dark blue. Loggerhead turtles also preferred untreated squid over red-dyed squid, whereas Kemp's ridley showed the opposite response. Field trials of blue-dyed bait were conducted on commercial fishing boats in the Gulf of Papagayo, Costa Rica, where ...


Flood Dispersal And Deposition By Near-Bed Gravitational Sediment Flows And Oceanographic Transport: A Numerical Modeling Study Of The Eel River Shelf, Northern California, Courtney K. Harris, Peter A. Traykovski, W. Rockwell Geyer Jan 2005

Flood Dispersal And Deposition By Near-Bed Gravitational Sediment Flows And Oceanographic Transport: A Numerical Modeling Study Of The Eel River Shelf, Northern California, Courtney K. Harris, Peter A. Traykovski, W. Rockwell Geyer

VIMS Articles

[1] A large flood of the Eel River, northern California, created a thick sediment deposit between water depths of 50 and 70 m in January 1997. The freshwater plume, however, confined sediment delivery to water depths shallower than 30 m. Mechanisms proposed to explain the apparent cross-shelf transport include dispersal by oceanographic currents, resuspension by energetic waves, and gravitationally forced transport of a thin layer of fluidized mud. Field observations indicate that these processes were all active but cannot determine their relative significance or whether these mechanisms alone explain the location, size, and timing of deposition. Approximately 30% of the ...


Observations On The Life History Of The Barndoor Skate, Dipturus Laevis, On Georges Bank (Western North Atlantic), Todd Gedamke, William D. Dupaul, John A. Musick Jan 2005

Observations On The Life History Of The Barndoor Skate, Dipturus Laevis, On Georges Bank (Western North Atlantic), Todd Gedamke, William D. Dupaul, John A. Musick

VIMS Articles

The barndoor skate (Dipturus laevis) has been reported to be close to extinction in parts of its northern range and is believed to be particularly vulnerable to fishing mortality due to its relatively large size. A lack of basic life history information, however, has hampered an accurate assessment and management of north Atlantic populations. In an attempt to fill this void, information was collected from 2 310 specimens caught during commercial sea scallop dredging in the southern section of Georges Bank Closed Area II. Eighty-seven fish were determined to be mature from a visual inspection of reproductive tracts and the ...


Toward Identification Of Larval Sailfish (Istiophorus Platypterus), White Marlin (Tetrapturus Albidus), And Blue Marlin (Makaira Nigricans) In The Western North Atlantic Ocean, Stacy A. Luthy, Robert K. Cowen, Joseph E. Serafy, Jan Mcdowell Jan 2005

Toward Identification Of Larval Sailfish (Istiophorus Platypterus), White Marlin (Tetrapturus Albidus), And Blue Marlin (Makaira Nigricans) In The Western North Atlantic Ocean, Stacy A. Luthy, Robert K. Cowen, Joseph E. Serafy, Jan Mcdowell

VIMS Articles

The identification of larval istiophorid billfishes from the western North Atlantic Ocean has long been problematic. In the present study, a molecular technique was used to positively identify 27 larval white marlin (Tetrapturus albidus), 96 larval blue marlin (Makaira nigricans), and 591 larval sailfish (Istiophorus platypterus) from the Straits of Florida and the Bahamas. Nine morphometric measurements were taken for a subset of larvae (species known), and lower jaw pigment patterns were recorded on a grid. Canonical variates analysis (CVA) was used to reveal the extent to which the combination of morphometric, pigment pattern, and month of capture information was ...


Effect Of Homogenate From Different Oyster Species On Perkinsus Marinus Proliferation And Subtilisin Gene Transcription, Gd Brown, Sl Kaattari, Kimberly S. Reece Jan 2005

Effect Of Homogenate From Different Oyster Species On Perkinsus Marinus Proliferation And Subtilisin Gene Transcription, Gd Brown, Sl Kaattari, Kimberly S. Reece

VIMS Articles

The modulation of Perkinsus marinus proliferation and subtilisin gene transcription by host (oyster) tissue was examined. Perkinsus rnarinus cells were cultured for 4 weeks in media supplemented with extract from either one of four different Crassostrea virginica stocks or with extract from one of two other Crassostrea species, C. ariakensis and C. gigas. After 4 weeks in culture, we determined cell counts and relative subtilisin gene transcription levels using quantitative real-time polymerise chain reaction (qRTPCR). Cell proliferation and subtilisin gene transcription were significantly lower when P. marinus' cells were grown in the presence of homogenate from any of the three ...


Northern Quahog (Hard Clam) Mercenaria Mercenaria Abundance And Habitat Use In Chesapeake Bay, Roger L. Mann, Jm Harding, Melissa Southworth, Ja Wesson Jan 2005

Northern Quahog (Hard Clam) Mercenaria Mercenaria Abundance And Habitat Use In Chesapeake Bay, Roger L. Mann, Jm Harding, Melissa Southworth, Ja Wesson

VIMS Articles

Recent (2001-2002) surveys of hard clam Mercenaria mercenaria density and distribution, using patent tongs in a stratified random design (n = 7,358 stations) in lower Chesapeake Bay are not consistent with historic descriptions of clam habitats and densities. The highest average densities observed, up to 3.1 clams m(-2), were in the lower James River. The highest modern average density observed is half that of clam densities commonly observed in these same habitats during the early 1970s. Current distribution is significantly affected by water depth and substrate composition. Hard clam density in Chesapeake Bay is positively associated with increasing ...


Performance Of "Natural Dermo-Resistant" Oyster Stocks-Survival, Disease, Growth, Condition And Energy Reserves, Vg Encomio, Sm Stickler, Standish K. Allen Jr., Fl Chu Jan 2005

Performance Of "Natural Dermo-Resistant" Oyster Stocks-Survival, Disease, Growth, Condition And Energy Reserves, Vg Encomio, Sm Stickler, Standish K. Allen Jr., Fl Chu

VIMS Articles

To determine if natural populations of the eastern oyster possess resistance to Perkinsus marinus, progeny representing several oyster stocks from the Chesapeake Bay and the Gulf of Mexico were deployed at two sites within the Chesapeake Bay. Mortality, P. marinas infection (prevalence and intensity), shell height, condition index, and energy reserves (glycogen, protein, and lipid) were compared between these stocks. Oyster stocks from the Chesapeake Bay had higher intensities of Dermo infection than Louisiana stocks, with differences among individual stocks. Throughout the 2-y study, a natural Dermo-resistant stock from Tangier Sound (CTS), was identified. Despite infection intensities approaching those of ...