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Full-Text Articles in Life Sciences

Characterization Of Microsporidian Ameson Herrnkindi Sp. Nov. Infecting Caribbean Spiny Lobsters Panulirus Argus, Hamish J. Small, Gd Stentiford, Dc Behringer, Ma Freeman, Nam Atherley, Kimberly S. Reece, Jeffrey D. Shields Oct 2019

Characterization Of Microsporidian Ameson Herrnkindi Sp. Nov. Infecting Caribbean Spiny Lobsters Panulirus Argus, Hamish J. Small, Gd Stentiford, Dc Behringer, Ma Freeman, Nam Atherley, Kimberly S. Reece, Jeffrey D. Shields

VIMS Articles

The Caribbean spiny lobster Panulirus argus supports a large and valuable fishery in the Caribbean Sea. In 2007-2008, a rare microsporidian parasite with spore characteristics typical of the Ameson genus was detected in 2 spiny lobsters from southeast Florida (FL). However, the parasite species was not confirmed by molecular analyses. To address this deficiency, reported here are structural and molecular data on single lobsters displaying comparable ‘cotton-like’ abdominal muscle containing ovoid microsporidian spores found at different locations in FL in 2014 and 2018 and in Saint Kitts and Nevis Islands in 2017. In the lobster from 2014, multiple life stages ...


Parasitic Dinoflagellate Hematodinium Perezi Prevalence In Larval And Juvenile Blue Crabs Callinectes Sapidus From Coastal Bays Of Virginia, Hj Small, Jp Huchin-Mian, Ks Reece, Km Pagenkopp Lohan, Mj Butler Iv, Jd Shields Jun 2019

Parasitic Dinoflagellate Hematodinium Perezi Prevalence In Larval And Juvenile Blue Crabs Callinectes Sapidus From Coastal Bays Of Virginia, Hj Small, Jp Huchin-Mian, Ks Reece, Km Pagenkopp Lohan, Mj Butler Iv, Jd Shields

VIMS Articles

The parasitic dinoflagellate Hematodinium perezi infects the American blue crab Callinectes sapidus and other decapods along the Eastern seaboard and Gulf of Mexico coast of the USA. Large juvenile and adult blue crabs experience high mortality during seasonal outbreaks of H. perezi, but less is known about its presence in the early life history stages of this host. We determined the prevalence of H. perezi in megalopae and early benthic juvenile crabs from multiple locations along the Virginia portion of the Delmarva Peninsula. The DNA of H. perezi was not detected in any megalopae collected from several locations within the ...


Bottom-Up Control Of Parasites, David S. Johnson, Richard Heard Oct 2017

Bottom-Up Control Of Parasites, David S. Johnson, Richard Heard

VIMS Articles

Parasitism is a fundamental ecological interaction. Yet we understand relatively little about the ecological role of parasites compared to the role of free-living organisms. Bottom-up theory predicts that resource enhancement will increase the abundance and biomass of free-living organisms. Similarly, parasite abundance and biomass should increase in an ecosystem with resource enhancement. We tested this hypothesis in a landscape-level experiment in which salt marshes (60,000 m2 each) received elevated nutrient concentrations via flooding tidal waters for 11 yr to mimic eutrophication. Nutrient enrichment elevated the densities of the talitrid amphipod, Orchestia grillus, and the density and biomass of its ...


Characterization Of A Rediscovered Haplosporidian Parasite From Cultured Penaeus Vannamei, Lm Nunam, Dv Lightner, Cr Pantoja, Na Stokes, Kimberly S. Reece Feb 2007

Characterization Of A Rediscovered Haplosporidian Parasite From Cultured Penaeus Vannamei, Lm Nunam, Dv Lightner, Cr Pantoja, Na Stokes, Kimberly S. Reece

VIMS Articles

Mortalities of Penaeus vannamei, cultured in ponds in Belize, Central America, began during the last part of the grow-out cycle during the cold weather months from September 2004 through February 2005. Tissue squashes of infected hepatopancreata and histological examination of infected shrimp revealed that the mortalities might have been caused by an endoparasite. To confirm the diagnosis, DNA was extracted from ethanol preserved hepatopancreata and the small-subunit rRNA gene was sequenced. The 1838 by sequence was novel and phylogenetic analysis placed the P. vannamei parasite within the phylum Haplosporidia as a sister taxon to a clade that includes Bonamia and ...


Mortality And Hematology Of Blue Crabs, Callinectes Sapidus, Experimentally Infected With The Parasitic Dinoflagellate Hematodinium Perezi, Jeffrey D. Shields, Christopher M. Squyars Jan 2000

Mortality And Hematology Of Blue Crabs, Callinectes Sapidus, Experimentally Infected With The Parasitic Dinoflagellate Hematodinium Perezi, Jeffrey D. Shields, Christopher M. Squyars

VIMS Articles

On the eastern seaboard of the United States, populations of the blue crab, Callinectes sapidus, experi-ence recurring outbreaks of a parasitic dinoflagellate, Hematodinium perezi. Epizootics fulminate in summer and autumn causing mortalities in high-salinity embayments and estuaries. In laboratory studies, we experimentally investigated host mortality due to the disease, assessed differential hemato-logical changes in infected crabs, and examined proliferation of the parasite.


Potential Role Of Protease-Antiprotease Interactions In Perkinsus Marinus Infection In Crassostrea Spp., M Faisal, Jl Oliver, Sl Kaataari Jan 1999

Potential Role Of Protease-Antiprotease Interactions In Perkinsus Marinus Infection In Crassostrea Spp., M Faisal, Jl Oliver, Sl Kaataari

VIMS Articles

Perkinsus marinus causes devastating losses in populations of the eastern oyster (Crassostrea virginica). Our studies have demonstrated that P. marinus secretes extracellular serine proteases which enhance parasite propagation and compromise host defences. Crassostrea virginica. however, possesses several inhibitors of these proteases. The Pacific oyster (C. gigas) is resistant to P. marinus and possesses protease inhibitors with significantly higher specific activities than those in C. virginica. Interestingly, Crassostrea spp. themselves, elaborate metalloprotease activities which can be detected in their plasma, and are increased during P. marinus infections. Together our work suggests that there may be a broad spectrum of humoral host ...


Environmental Factors And The Infectious Disease Caused By The Protozoan Parasite, Perkinsus Marinus, In Eastern Oysters (Crassostrea Virginica), Fle Chu Jan 1999

Environmental Factors And The Infectious Disease Caused By The Protozoan Parasite, Perkinsus Marinus, In Eastern Oysters (Crassostrea Virginica), Fle Chu

VIMS Articles

Temperature and salinity are two important factors limiting the distribution and abundance of Perkinsus marinus, a protozoan parasite of Eastern oysters (Crassostrea virginica). Results of laboratory studies ale consistent with field observations and clearly demonstrate that P. marinus susceptibility and disease advancement are positively correlated with temperature, salinity and in situ number of infective cells. Laboratory findings also suggest that environmental degradation may enhance the epizootic, although disease caused by P. marinus in oysters is known to be predominantly exacerbated by elevated temperature and salinity. Oysters cellular defence mechanisms appear ineffective in defence against P. marinus. Also, pollutant esposure caused ...


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 ...


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 ...


Development Of A Protein-Free Chemically Defined Culture Medium For The Propagation Of The Oyster Pathogen Perkinsus Marinus, Jf Lapeyre, M Faisal Jan 1997

Development Of A Protein-Free Chemically Defined Culture Medium For The Propagation Of The Oyster Pathogen Perkinsus Marinus, Jf Lapeyre, M Faisal

VIMS Articles

In the present study we describe a protein-free, chemically defined culture medium, designated JL-ODRP-3, which supports the propagation of Perkinsus marinus, a parasite of the eastern oyster, Crassotrea virginica. P. marinus adapted rapidly to the defined medium and the growth rate of the protozoan increased significantly following a few subcultures. Two isolates of P. marinus, one from the Chesapeake Bay (Virginia) and the other from the Gulf of Mexico (Texas) were cultured for at least ten passes. The doubling times far the isolates from Virginia and Texas, in Jog phase, were 18 +/- 1.2 and 28.6 +/- 3.2 hours ...


Optimal Culture Conditions For The Propagation Of The Oyster Pathogen Perkinsus Marinus (Apicomplexa) In Protein Deficient Medium, Jf Lapeyre, M Faisal Jan 1996

Optimal Culture Conditions For The Propagation Of The Oyster Pathogen Perkinsus Marinus (Apicomplexa) In Protein Deficient Medium, Jf Lapeyre, M Faisal

VIMS Articles

The protozoan, Perkinsus marinus, acclimated and proliferated in the culture medium JL-ODRP-1 without bovine serum albumin. The principal culture conditions for the optimal propagation of P. marinus in this protein deficient culture medium, were determined. The greatest growth rates of the parasite occurred at 28 degrees C, 661 mOsm/kg and pH 7.5. Decreasing seeding densities from 16 x 10(5) to 1 x 10(5) also increased growth rate. After several passages in the absence of 5% CO2 tension, the growth rate of P. marinus was similar to its original value in the presence of 5% CO2 tension ...


Epizootiology Of Late Summer And Fall Infections Of Oysters By Haplosporidium Nelsoni, And Comparisons To Annual Life Cycle Of Haplosporidium Costalis, A Typical Haplosporidan, J. D. Andrews Jan 1982

Epizootiology Of Late Summer And Fall Infections Of Oysters By Haplosporidium Nelsoni, And Comparisons To Annual Life Cycle Of Haplosporidium Costalis, A Typical Haplosporidan, J. D. Andrews

VIMS Articles

The two haplosporidan parasites that cause diseases of oysters along the middle North Atlantic coast of North America differ in their habitats, in timing of oyster mortalities, and in their adaptations to the host. Haplosporidium nelsoni (MSX) kills oysters throughout the year over a wide range of salinities (about 15 to 30 ppt). It has a long infective period of nearly 6 months. This pathogen rarely completes sporulation in its life cycle in oysters. It is highly pathogenic and exhibits irregular activity suggesting that it is poorly adapted to the host species. In contrast, Haplosporidium costalis (SSO) has a short ...