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Perkinsus Marinus Tissue Distribution And Seasonal Variation In Oysters Crassostrea Virginica From Florida, Virginia And New York, Lm Oliver, Ws Fisher, Se Ford, Lm Ragone Calvo, Em Burreson, Et Al Sep 1998

Perkinsus Marinus Tissue Distribution And Seasonal Variation In Oysters Crassostrea Virginica From Florida, Virginia And New York, Lm Oliver, Ws Fisher, Se Ford, Lm Ragone Calvo, Em Burreson, Et Al

VIMS Articles

Perkinsus marinus infection intensity was measured in eastern oysters Crassostrea virginica collected in October and December 1993, and March, May, and July 1994 from 3 U.S. sites: Apalachicola Bay (FL), Chesapeake Bay (VA), and Oyster Bay (Mr'). Gill, mantle, digestive gland. adductor muscle, hemolymph, and remaining tissue (including gonadal material and rectum) were dissected from 20 oysters from each site at each collection time. Samples were separately diagnosed for P. marin us infections by incubation in Ray's Fluid Thioglycollate Medium (RFTM) and subsequent microscopic quantification of purified enlarged hypnospores. At all sampling times and sites, average P. marinus infection intensity …


Molecular Insights Into The Population Structures Of Cosmopolitan Marine Fishes, John Graves Sep 1998

Molecular Insights Into The Population Structures Of Cosmopolitan Marine Fishes, John Graves

VIMS Articles

Many marine fishes are cosmopolitan, occurring in continuous (e.g., circumtropical) or discontinuous (e.g., antitropical) distributions. Little is known of the genetic basis of population structure of these species, even though several support extensive fisheries. To develop a database that would facilitate comparison of the population structures among cosmopolitan fishes we consistently included restriction fragment length polymorphism (RFLP) analysis of mitochondrial DNA (mtDNA) as a common approach to our investigations of these species. This article presents a review of those analyses. Considerable intra`specific genetic variation was revealed within all cosmopolitan marine species. Continuously distributed species displayed population structures ranging from a …


Histopathological Alterations Associated With Perkinsus Spp. Infection In The Softshell Clam Mya Arenaria, Sm Mclaughlin, M Faisal Sep 1998

Histopathological Alterations Associated With Perkinsus Spp. Infection In The Softshell Clam Mya Arenaria, Sm Mclaughlin, M Faisal

VIMS Articles

Softshell clams (Mya arenaria) collected from the Chester River in the upper Chesapeake Bay showed the presence of Perkinsus spp, in similar to 12 % (28/240) Of clams examined. The infection seems to run a mild course with the host prevailing in encapsulating invading parasites. The gills appear to be the major site of infection, however, the parasite was also found in the digestive gland, gonads, and kidneys and occasionally in the tissue and sinuses of adductor muscles. Typically, clusters of protozoal cells were embedded in on amorphous PAS-positive substrate and were surrounded by one or more layers of granulocytes. …


Prevalence And Distribution Of Qpx, Quahog Parasite Unknown, In Hard Clams Mercenaria Mercenaria In Virginia, Usa, Lm Ragone Calvo, Jg Walker, Em Burreson Jul 1998

Prevalence And Distribution Of Qpx, Quahog Parasite Unknown, In Hard Clams Mercenaria Mercenaria In Virginia, Usa, Lm Ragone Calvo, Jg Walker, Em Burreson

VIMS Articles

In July 1996, the Virginia Institute of Marine Science initiated a sampling program to examine wild and cultured hard clams Mercenaria mercenaria for QPX, Quahog Parasite Unknown, a protistan parasite associated with severe mortalities of hard clams in localized areas in maritime Canada and Massachusetts, USA. The sampling program set out to seasonally monitor wild clams from one site, James River, Virginia, and cultured clams from 2 sites, Chincoteague Bay and Mattawoman Creek, Virginia. Histological examination of initial samples revealed 8% prevalence of the parasite in 1-2 yr old cultured clams in Chincoteague Bay. This is the first documentation of …


Evaluation Of Toxicity Of Oxytetracycline On Growth Of Captive Nurse Sharks, Ginglymostoma Cirratum, James Gelsleichter, Enric Cortes, Charles A. Manire, R. Hueter, John Musick Jan 1998

Evaluation Of Toxicity Of Oxytetracycline On Growth Of Captive Nurse Sharks, Ginglymostoma Cirratum, James Gelsleichter, Enric Cortes, Charles A. Manire, R. Hueter, John Musick

VIMS Articles

No abstract provided.


In Vitro Propagation Of Two Perkinsus Species From The Softshell Clam Mya Arenaria, Sm Mclaughlin, M Faisal Jan 1998

In Vitro Propagation Of Two Perkinsus Species From The Softshell Clam Mya Arenaria, Sm Mclaughlin, M Faisal

VIMS Articles

Two continuous, axenic cultures of Perkinsus spp. (H49 and G117)were obtained from the softshell clam Mya arenaria collected from Swan Point in the Chester River, Chesapeake Bay (Maryland).

Isolate H49 was obtained from the hemolymph of a heavily infected clam. Except for their larger size, H49 trophozoites and schizonts exhibited the characteristic morphology of Perkinsus marinus and divided by schizogony. Isolate G117 was obtained from a combined gill/palp sample of a moderately infected clam. Unlike H49, vegetative forms (trophozoites and schizonts) of G117 were present along with prezoosporulation stages in the same culture. In culture, G117 cells multiplied by both …


Global Phylogeography Of Mackerels Of The Genus Scomber, Daniel Scoles, Bruce B. Collette, John Graves Jan 1998

Global Phylogeography Of Mackerels Of The Genus Scomber, Daniel Scoles, Bruce B. Collette, John Graves

VIMS Articles

Inter- and intraspecific genetic relationships among and within three species of mackerels of the genus Scomber were investigated by restriction site analysis of the whole mitochondrial (mt) DNA genome and direct sequence analysis of the mitochondrial cytochrome b gene. A total of 15 samples, averaging 19 individuals each, were collected from geographically isolated populations throughout the ranges of S. scombrus (two samples), S, australasicus (five samples), and S. japonicus (eight samples). Restriction site analysis with 12 restriction enzymes revealed substantial genetic variation within each species. Sample haplotype diversities ranged from 0.28 to 0.95, and nucleotide sequence diversities from 0.13% to …