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Full-Text Articles in Life Sciences
A Deterministic Model For Understanding Nonlinear Viral Dynamics In Oysters, Qubin Qin, Jian Shen, Kimberly S. Reece
A Deterministic Model For Understanding Nonlinear Viral Dynamics In Oysters, Qubin Qin, Jian Shen, Kimberly S. Reece
VIMS Articles
Contamination of oysters with a variety of viruses is one key pathway to trigger outbreaks of massive oyster mortality as well as human illnesses, including gastroenteritis and hepatitis. Much effort has gone into examining the fate of viruses in contaminated oysters, yet the current state of knowledge of nonlinear virus-oyster interactions is not comprehensive because most studies have focused on a limited number of processes under a narrow range of experimental conditions. A framework is needed for describing the complex nonlinear virus-oyster interactions. Here, we introduce a mathematical model that includes key processes for viral dynamics in oysters, such as …
Contrasting Controls On Seasonal And Spatial Distribution Of Marine Cable Bacteria (Candidatus Electrothrix) And Beggiatoaceae In Seasonally Hypoxic Chesapeake Bay, Sairah Y. Malkin, Pinky Liau, Carol Kim, Kalev G. Hantsoo, Maya L. Gomes, Bongkeun Song
Contrasting Controls On Seasonal And Spatial Distribution Of Marine Cable Bacteria (Candidatus Electrothrix) And Beggiatoaceae In Seasonally Hypoxic Chesapeake Bay, Sairah Y. Malkin, Pinky Liau, Carol Kim, Kalev G. Hantsoo, Maya L. Gomes, Bongkeun Song
VIMS Articles
Marine cable bacteria (Candidatus Electrothrix) and large colorless sulfur-oxidizing bacteria (e.g., Beggiatoaceae) are widespread thiotrophs in coastal environments but may exert different influences on biogeochemical cycling. Yet, the factors governing their niche partitioning remain poorly understood. To map their distribution and evaluate their growth constraints in a natural setting, we examined surface sediments across seasons at two sites with contrasting levels of seasonal oxygen depletion in Chesapeake Bay using microscopy coupled with 16S rRNA gene amplicon sequencing and biogeochemical characterization. We found that cable bacteria, dominated by a single phylotype closely affiliated to Candidatus Electrothrix communis, flourished during …
Effects Of Two Toxin-Producing Harmful Algae, Alexandrium Catenella And Dinophysis Acuminata (Dinophyceae), On Activity And Mortality Of Larval Shellfish, Sarah K.D. Pease, Michael L. Brosnahan, Marta P. Sanderson, Juliette L. Smith
Effects Of Two Toxin-Producing Harmful Algae, Alexandrium Catenella And Dinophysis Acuminata (Dinophyceae), On Activity And Mortality Of Larval Shellfish, Sarah K.D. Pease, Michael L. Brosnahan, Marta P. Sanderson, Juliette L. Smith
VIMS Articles
Harmful algal bloom (HAB) species Alexandrium catenella and Dinophysis acuminata are associated with paralytic shellfish poisoning (PSP) and diarrhetic shellfish poisoning (DSP) in humans, respectively. While PSP and DSP have been studied extensively, less is known about the effects of these HAB species or their associated toxins on shellfish. This study investigated A. catenella and D. acuminata toxicity in a larval oyster (Crassostrea virginica) bioassay. Larval activity and mortality were examined through 96-h laboratory exposures to live HAB cells (10–1000 cells/mL), cell lysates (1000 cells/mL equivalents), and purified toxins (10,000 cells/mL equivalents). Exposure to 1000 cells/mL live or lysed D. …
A Rapid Phenotype Change In The Pathogen Perkinsus Marinus Was Associated With A Historically Significant Marine Disease Emergence In The Eastern Oyster, Ryan Carnegie, Susan E. Ford, Rita K. Crockett, Peter R. Kingsley-Smith, Lydia M. Bienlien, Lucia S.L. Safi, Laura A. Whitefleet-Smith, Eugene M. Burreson
A Rapid Phenotype Change In The Pathogen Perkinsus Marinus Was Associated With A Historically Significant Marine Disease Emergence In The Eastern Oyster, Ryan Carnegie, Susan E. Ford, Rita K. Crockett, Peter R. Kingsley-Smith, Lydia M. Bienlien, Lucia S.L. Safi, Laura A. Whitefleet-Smith, Eugene M. Burreson
VIMS Articles
The protozoan parasite Perkinsus marinus, which causes dermo disease in Crassostrea virginica, is one of the most ecologically important and economically destructive marine pathogens. The rapid and persistent intensification of dermo in the USA in the 1980s has long been enigmatic. Attributed originally to the effects of multi-year drought, climatic factors fail to fully explain the geographic extent of dermo’s intensification or the persistence of its intensified activity. Here we show that emergence of a unique, hypervirulent P. marinus phenotype was associated with the increase in prevalence and intensity of this disease and associated mortality. Retrospective histopathology of …
Comparative Study Of The Hemolymph Microbiome Between Live And Recently Dead American Lobsters Homarus Americanus, Jibom Jung, Patrick M. Gillevet, Masoumeh Sikaroodi, Jamal Andrews, Bk Song, Jeffrey D. Shields
Comparative Study Of The Hemolymph Microbiome Between Live And Recently Dead American Lobsters Homarus Americanus, Jibom Jung, Patrick M. Gillevet, Masoumeh Sikaroodi, Jamal Andrews, Bk Song, Jeffrey D. Shields
VIMS Articles
Lobsters and other crustaceans do not have sterile hemolymph. Despite this, little is known about the microbiome in the hemolymph of the lobster Homarus americanus. The purpose of this study was to characterize the hemolymph microbiome in lobsters. The lobsters were part of a larger study on the effect of temperature on epizootic shell disease, and several died during the course of the study, providing an opportunity to examine differences in the microbiomes between live and recently dead (1−24 h) animals. The hemolymph microbiomes of live lobsters was different from those in dead animals and both were different from the …
Molecular Mechanism Of Oil Induced Growth Inhibition In Diatoms Using Thalassiosira Pseudonana As The Model Species, Manoj Kamalanathan, Savannah Mapes, Jessica Hillhouse, Et Al
Molecular Mechanism Of Oil Induced Growth Inhibition In Diatoms Using Thalassiosira Pseudonana As The Model Species, Manoj Kamalanathan, Savannah Mapes, Jessica Hillhouse, Et Al
VIMS Articles
The 2010 Deepwater Horizon oil-spill exposed the microbes of Gulf of Mexico to unprecedented amount of oil. Conclusive evidence of the underlying molecular mechanism(s) on the negative effects of oil exposure on certain phytoplankton species such as Thalassiosira pseudonana is still lacking, curtailing our understanding of how oil spills alter community composition. We performed experiments on model diatom T. pseudonana to understand the mechanisms underpinning observed reduced growth and photosynthesis rates during oil exposure. Results show severe impairment to processes upstream of photosynthesis, such as light absorption, with proteins associated with the light harvesting complex damaged while the pigments were …
Effects Of Climate Change On Metabolite Accumulation In Freshwater And Marine Cyanobacteria, I-Shuo Huang, Xinping Hu, Hussain Abdulla, Paul V. Zimba
Effects Of Climate Change On Metabolite Accumulation In Freshwater And Marine Cyanobacteria, I-Shuo Huang, Xinping Hu, Hussain Abdulla, Paul V. Zimba
VIMS Articles
Global climate change and anthropogenic nutrient inputs are responsible for increased frequency of cyanobac- terial blooms that potentially contain 55 classes of bioactive metabolites. This study investigated the effects of CO2 availability and concomittant pH levels on two cyanobacteria that produce microcystins: a marine cf. Syne- chocystis sp. and a freshwater Microcystis aeruginosa. Cyanobacterial strains were semi-continuously cultured in mesotrophic growth media at pH 7.5, 7.8, 8.2, and 8.5 via a combination of CO2 addition and control of alkalinity. The cell concentration between treatments was not significantly different and nutrient availability was not lim- ited. Concentration of most known cyanobacterial …
Penaeid Shrimp In Chesapeake Bay: Population Growth And Black Gill Disease Syndrome, Troy D. Tuckey, Jillian L. Swinford, Mary C. Fabrizio, Hamish J. Small, Jeffrey D. Shields
Penaeid Shrimp In Chesapeake Bay: Population Growth And Black Gill Disease Syndrome, Troy D. Tuckey, Jillian L. Swinford, Mary C. Fabrizio, Hamish J. Small, Jeffrey D. Shields
VIMS Articles
Since 1991, the number of penaeid shrimp occurring in Virginia waters of Chesapeake Bay has steadily increased, prompting an interest in developing a fishery. Although development of a shrimp fishery in the Chesapeake Bay region could bring economic benefits, the fishery may be hampered by the presence of a disease syndrome known as shrimp black gill (sBG). The objectives of our study were to (1) describe the spatial distribution and abundance patterns of shrimp in Chesapeake Bay, (2) relate relative abundance of shrimp to habitat characteristics, and (3) determine the presence and seasonality of sBG to better understand disease dynamics …
Rhodomonas Pe545 Fluorescence Is Increased By Glycerol, Chanoknard Karnjanapak, I-Shuo Huang, Preyanut Jaroensuk, Et Al
Rhodomonas Pe545 Fluorescence Is Increased By Glycerol, Chanoknard Karnjanapak, I-Shuo Huang, Preyanut Jaroensuk, Et Al
VIMS Articles
Phycobilins are photosynthetic pigments found in three ecologically important groups of algae: cyanobacte- ria, red algae, and cryptophytes. These compounds are covalently attached to proteins, which can be technically difficult to analyze compared with other photosynthetic pigments (e.g., chlorophylls and carotenoids). In this study, glycerol was demonstrated to uncouple PE545 (phycoerythrin 545), the phycobilin complex of Rhodomonas spp., from its role as a light-harvesting pigment: the fluorescence signal was increased 15–34 times, and ETR (electron transport rate) was no longer light-dependent at high light intensities. Glycerol induced fluorescence provided a simple and inexpensive protocol to ascertain the pool size of …
Marine Harmful Algal Blooms (Habs) In The United States: History, Current Status And Future Trends, Donald M. Anderson, Elizabeth Fensin, Christopher J. Gobler, (...), Juliette L. Smith, Et Al
Marine Harmful Algal Blooms (Habs) In The United States: History, Current Status And Future Trends, Donald M. Anderson, Elizabeth Fensin, Christopher J. Gobler, (...), Juliette L. Smith, Et Al
VIMS Articles
Harmful algal blooms (HABs) are diverse phenomena involving multiple. species and classes of algae that occupy a broad range of habitats from lakes to oceans and produce a multiplicity of toxins or bioactive compounds that impact many different resources. Here, a review of the status of this complex array of marine HAB problems in the U.S. is presented, providing historical information and trends as well as future perspectives. The study relies on thirty years (1990–2019) of data in HAEDAT - the IOC-ICES-PICES Harmful Algal Event database, but also includes many other reports. At a qualitative level, the U.S. national HAB …
Disease Diagnostics And Potential Coinfections By Vibrio Coralliilyticus During An Ongoing Coral Disease Outbreak In Florida, Blake Ushijima, Julie L. Meyer, Sharon Thompson, Kelly Pitts, Michael F. Marusich, Jessica Tittl, Elizabeth Weatherup, Et Al
Disease Diagnostics And Potential Coinfections By Vibrio Coralliilyticus During An Ongoing Coral Disease Outbreak In Florida, Blake Ushijima, Julie L. Meyer, Sharon Thompson, Kelly Pitts, Michael F. Marusich, Jessica Tittl, Elizabeth Weatherup, Et Al
VIMS Articles
A deadly coral disease outbreak has been devastating the Florida Reef Tract since 2014. This disease, stony coral tissue loss disease (SCTLD), affects at least 22 coral species causing the progressive destruction of tissue. The etiological agents responsible for SCTLD are unidentified, but pathogenic bacteria are suspected. Virulence screens of 400 isolates identified four potentially pathogenic strains of Vibrio spp. subsequently identified as V. coralliilyticus. Strains of this species are known coral pathogens; however, cultures were unable to consistently elicit tissue loss, suggesting an opportunistic role. Using an improved immunoassay, the VcpA RapidTest, a toxic zinc-metalloprotease produced by …
Dihydrodinophysistoxin-1 Produced By Dinophysis Norvegica In The Gulf Of Maine, Usa And Its Accumulation In Shellfish, Jonathan R. Deeds, Whitney L. Stutts, Mary Dawn Celiz, Jill Macleod, Amy E. Hamilton, Bryant J. Lewis, David W. Miller, Kohl Kanwit, Juliette L. Smith, Et Al
Dihydrodinophysistoxin-1 Produced By Dinophysis Norvegica In The Gulf Of Maine, Usa And Its Accumulation In Shellfish, Jonathan R. Deeds, Whitney L. Stutts, Mary Dawn Celiz, Jill Macleod, Amy E. Hamilton, Bryant J. Lewis, David W. Miller, Kohl Kanwit, Juliette L. Smith, Et Al
VIMS Articles
Dihydrodinophysistoxin-1 (dihydro-DTX1, (M-H)−m/z 819.5), described previously from a marine sponge but never identified as to its biological source or described in shellfish, was detected in multiple species of commercial shellfish collected from the central coast of the Gulf of Maine, USA in 2016 and in 2018 during blooms of the dinoflagellate Dinophysis norvegica. Toxin screening by protein phosphatase inhibition (PPIA) first detected the presence of diarrhetic shellfish poisoning-like bioactivity; however, confirmatory analysis using liquid chromatography-tandem mass spectrometry (LC-MS/MS) failed to detect okadaic acid (OA, (M-H)−m/z 803.5), dinophysistoxin-1 (DTX1, (M-H)−m/z 817.5), or dinophysistoxin-2 (DTX2, (M-H) …
A Screening Tool For The Direct Analysis Of Marine And Freshwater Phycotoxins In Organic Spatt Extracts From The Chesapeake Bay, Michelle D. Onofiro, Claude R. Mallette, Allen R. Place, Juliette L. Smith
A Screening Tool For The Direct Analysis Of Marine And Freshwater Phycotoxins In Organic Spatt Extracts From The Chesapeake Bay, Michelle D. Onofiro, Claude R. Mallette, Allen R. Place, Juliette L. Smith
VIMS Articles
Many detection methods for phycotoxins, bioactive compounds produced by harmful algae, focus on one compound or a class of related compounds. Multiple harmful algal species often co-occur in the environment, however, emphasizing the need to analyze for the presence of multiple groups of marine and freshwater phycotoxins in environmental samples, e.g., extracts from solid phase adsorption toxin tracking (SPATT). Two methods were developed to screen for 13 phycotoxins (microcystin-RR, -LR, -YR, azaspiracid-1, -2, karlotoxin 3, goniodomin A, brevetoxin-2, yessotoxin, pectenotoxin-2, dinophysistoxin-1, -2, and okadaic acid) in organic SPATT extracts using ultra-performance liquid chromatography–tandem mass spectrometry (UPLC-MS/MS) equipped with a trapping …
Impact Of Vaccination And Pathogen Exposure Dosage On Shedding Kinetics Of Infectious Hematopoietic Necrosis Virus (Ihnv) In Rainbow Trout, Darbi R. Jones, Barbara J. Rutan, Ar Wargo
Impact Of Vaccination And Pathogen Exposure Dosage On Shedding Kinetics Of Infectious Hematopoietic Necrosis Virus (Ihnv) In Rainbow Trout, Darbi R. Jones, Barbara J. Rutan, Ar Wargo
VIMS Articles
Vaccine efficacy in preventing clinical disease has been well characterized. However, vaccine impacts on transmission under diversefied conditions, such as variable pathogen exposure dosages, are not fully understood. We evaluated the impacts of vaccination on disease-induced host mortality and shedding of infectious hematopoietic necrosis virus (IHNV) in Rainbow Trout Oncorhynchus mykiss. Fish, in up to three different genetic lines, were exposed to different dosages of IHNV to simulate field variability. Mortality and viral shedding of each individual fish were quantified over the course of infection. As the exposure dosage increased, mortality, number offish shedding virus,daily virus quantity shed, and total …
First Comparison Of French And Australian Oshv-1 Μvars By Bath Exposure, Ca Burge, Kimberly S. Reece, Ak Dhar, P Kirkland, B Morga, L Dégremont, N Faury, B Whipple, A Macintyre, C Friedman
First Comparison Of French And Australian Oshv-1 Μvars By Bath Exposure, Ca Burge, Kimberly S. Reece, Ak Dhar, P Kirkland, B Morga, L Dégremont, N Faury, B Whipple, A Macintyre, C Friedman
VIMS Articles
Economically devastating mortality events of farmed and wild shellfish due to infectious disease have been reported globally. Currently, one of the most significant disease threats to Pacific oyster Crassostrea gigas culture is the ostreid herpesvirus 1 (OsHV-1), in particular the emerging OsHV-1 microvariant genotypes. OsHV-1 microvariants (OsHV-1 μvars) are spreading globally, and concern is high among growers in areas unaffected by OsHV-1. No study to date has compared the relative virulence among variants. We provide the first challenge study comparing survival of naïve juvenile Pacific oysters exposed to OsHV-1 μvars from Australia (AUS μvar) and France (FRA μvar). Oysters challenged …
Population Structure Of The Blue Crab Callinectes Sapidus In The Maryland Coastal Bays, Kristen A. Lycett, Jeffrey D. Shields, J. Sook Chung, Joseph S. Pitula
Population Structure Of The Blue Crab Callinectes Sapidus In The Maryland Coastal Bays, Kristen A. Lycett, Jeffrey D. Shields, J. Sook Chung, Joseph S. Pitula
VIMS Articles
The population structure of the blue crab Callinectes sapidus was examined in the Maryland Coastal Bays (MCB) from 2014 to 2016. Crabs were sampled from April to December of each year. Size–frequency distributions showed a strong seasonal cycle, with small crabs being abundant in April, increasing in size through September, with adult crabs observed in the highest proportions from August through October of each year. A subsample of crabs was assayed for hemolymph ecdysone concentrations to examine molting patterns in field-collected blue crabs. Molting was observed throughout the sampling season, peaking in April for immature crabs, with lows in all …
Microplastics Affect Sedimentary Microbial Communities And Nitrogen Cycling, Meredith E. Seeley, Bk Song, Renia Passie, Robert C. Hale
Microplastics Affect Sedimentary Microbial Communities And Nitrogen Cycling, Meredith E. Seeley, Bk Song, Renia Passie, Robert C. Hale
VIMS Articles
Microplastics are ubiquitous in estuarine, coastal, and deep sea sediments. The impacts of microplastics on sedimentary microbial ecosystems and biogeochemical carbon and nitrogen cycles, however, have not been well reported. To evaluate if microplastics influence the composition and function of sedimentary microbial communities, we conducted a microcosm experiment using salt marsh sediment amended with polyethylene (PE), polyvinyl chloride(PVC), polyurethane foam (PUF) or polylactic acid (PLA) microplastics. We report that the presence of microplastics alters sediment microbial community composition and nitrogen cycling processes. Compared to control sediments without microplastic, PUF- and PLA-amended sediments promote nitrification and denitrification, while PVC amendment inhibits …
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
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 …
Climate Change Enhances Disease Processes In Crustaceans: Case Studies In Lobsters, Crabs, And Shrimps, Jeffrey D. Shields
Climate Change Enhances Disease Processes In Crustaceans: Case Studies In Lobsters, Crabs, And Shrimps, Jeffrey D. Shields
VIMS Articles
Climate change has resulted in increasing temperature and acidification in marine systems. Rising temperature and acidification act as stressors that negatively affect host barriers to infection, thus enhancing disease processes and influencing the emergence of pathogens in ecologically and commercially important species. Given that crustaceans are ectotherms, changes in temperature dominate their physiological and immunological responses to microbial pathogens and parasites. Because of this, the thermal ranges of several crustacean hosts and their pathogens can be used to project the outcomes of infections. Host factors such as molting, maturation, respiration, and immune function are strongly influenced by temperature, which in …
Tracking Triploid Mortalities Of Eastern Oysters Crassostrea Virginica In The Virginia Portion Of The Chesapeake Bay, Eric Guevelou, Ryan Carnegie, Ja Moss, Karen Hudson, Kimberly S. Reece, Molly M. Rybovich, Standish K. Allen Jr.
Tracking Triploid Mortalities Of Eastern Oysters Crassostrea Virginica In The Virginia Portion Of The Chesapeake Bay, Eric Guevelou, Ryan Carnegie, Ja Moss, Karen Hudson, Kimberly S. Reece, Molly M. Rybovich, Standish K. Allen Jr.
VIMS Articles
Since 2012, aquacultured eastern oysters Crassostrea virginica have been reported by oyster farmers to display mortality approaching 30%, and in some cases 85%, in areas of the lower Chesapeake Bay, VA. Based on accounts from industry, this mortality has typically affected 1-y-old oysters between May and early July, and has tended to occur in triploid oysters, which represent the vast bulk of production in the area. During this period, samples submitted for pathology have not revealed the presence of major pathogens as a cause. In 2015, to gain deeper insight into this mortality and determine whether specific sites, ploidy condition, …
Method For Serial Passage Of Infectious Hematopoietic Necrosis Virus (Ihnv) In Rainbow Trout, Juliette Doumayrou, M. Gray Ryan, Andrew R. Wargo
Method For Serial Passage Of Infectious Hematopoietic Necrosis Virus (Ihnv) In Rainbow Trout, Juliette Doumayrou, M. Gray Ryan, Andrew R. Wargo
VIMS Articles
Transmission is a fundamental component of pathogen fitness. A better understanding of pathogen transmission can greatly improve disease management. In particular, controlled studies of multiple rounds of natural transmission (i.e. serial passage) can provide powerful epidemiological and evolutionary inferences. However, such studies are possible in only a few systems because of the challenges in successfully initiating and maintaining transmission in the laboratory. Here we developed an efficient and reproducible cohabitation method for conducting controlled experiments investigating the effects of serial passage on infectious hematopoietic necrosis virus (IHNV) in rainbow trout. This method was used to investigate the transmission efficiency and …
Prey Lysate Enhances Growth And Toxin Production In An Isolate Of Dinophysis Acuminata, Han Gao, Mengmeng Tong, Xinlong An, Juliette L. Smith
Prey Lysate Enhances Growth And Toxin Production In An Isolate Of Dinophysis Acuminata, Han Gao, Mengmeng Tong, Xinlong An, Juliette L. Smith
VIMS Articles
The physiological and toxicological characteristics of Dinophysis acuminata have been increasingly studied in an attempt to better understand and predict diarrhetic shellfish poisoning (DSP) events worldwide. Recent work has identified prey quantity, organic nitrogen, and ammonium as likely contributors to increased Dinophysis growth rates and/or toxicity. Further research is now needed to better understand the interplay between these factors, for example, how inorganic and organic compounds interact with prey and a variety of Dinophysis species and/or strains. In this study, the exudate of ciliate prey and cryptophytes were investigated for an ability to support D. acuminata growth and toxin production …
Rising Temperatures, Molting Phenology, And Epizootic Shell Disease In The American Lobster, Maya Groner, Jeffrey D. Shields, Df Landers, J Swenarton, Jm Hoenig
Rising Temperatures, Molting Phenology, And Epizootic Shell Disease In The American Lobster, Maya Groner, Jeffrey D. Shields, Df Landers, J Swenarton, Jm Hoenig
VIMS Articles
Phenological mismatchmaladaptive changes in phenology resulting from altered timing of environmental cuesis an increasing concern in many ecological systems, yet its effects on disease are poorly characterized. American lobster (Homarus americanus) is declining at its southern geographic limit. Rising seawater temperatures are associated with seasonal outbreaks of epizootic shell disease (ESD), which peaks in prevalence in the fall. We used a 34-year mark-recapture data set to investigate relationships between temperature, molting phenology, and ESD in Long Island Sound, where temperatures are increasing at 0.4 degrees C per decade. Our analyses support the hypothesis that phenological mismatch is linked to the …
Investigating The Life Cycle Of Haplosporidium Nelsoni (Msx), Se Ford, Na Stokes, Ka Alcox, Bsf Kraus, Rochelle Barber, Ryan Carnegie, Em Burreson
Investigating The Life Cycle Of Haplosporidium Nelsoni (Msx), Se Ford, Na Stokes, Ka Alcox, Bsf Kraus, Rochelle Barber, Ryan Carnegie, Em Burreson
VIMS Articles
Attempts to decipher the life cycle of Haplosporidium nelsoni began almost immediately after it was identified as the pathogen causing MSX disease in eastern oysters, Crassostrea virginica. But transmission experiments failed and the spore stage, characteristic of haplosporidans, was extremely rare. Researchers concluded that another host was involved: an intermediate host in which part of the life cycle was produced, or-if the oyster was an accidental host-an alternate host that produces infective elements. A later finding that spores were found more often in spat (< 1 y old) than in adults revived the idea of direct transmission between oysters. The new findings and the availability of molecular diagnostics led us to revive life cycle investigations. Over several years, oyster spat were examined for spores and searched for H. nelsoni in potential non-oyster hosts using both histological and polymerase chain reaction (PCR) methodologies. …
Development Of Rapid Diagnostic Techniques For Idiopathic Blindness In The American Lobster, Homarus Americanus, From Eastern Long Island Sound, Addison T. Ochs, Jeffrey D. Shields, Mitch S. Hatzipetro, Barbara Somers, Kathleen M. Castro
Development Of Rapid Diagnostic Techniques For Idiopathic Blindness In The American Lobster, Homarus Americanus, From Eastern Long Island Sound, Addison T. Ochs, Jeffrey D. Shields, Mitch S. Hatzipetro, Barbara Somers, Kathleen M. Castro
VIMS Articles
Idiopathic blindness is a condition that afflicts approximately 50% of the lobsters, Homarus americanus H. Milne-Edwards, 1837, in Long Island Sound (LIS). The condition occurs in lobsters from LIS and Narragansett Bay, but has lower prevalence levels in the Gulf of Maine. Grossly, the condition presents as patches of cloudy, gray-colored regions in the eyes of afflicted animals. Histologically, the ommatidia show signs of altered pigment distribution, necrosis of the optic nerves and rhabdoms, and hemocyte infiltration through the protective basement membrane separating the ommatidia from the optic nerves. Severe lesions show areas with necrotic ommatidia and nearly complete loss …
Increasing Prevalence Of Epizootic Shell Disease In American Lobster From The Nearshore Gulf Of Maine, Kathleen M. Reardon, Carl J. Wilson, Patrick M. Gillevet, Masoumeh Sikaroodi, Jeffrey D. Shields
Increasing Prevalence Of Epizootic Shell Disease In American Lobster From The Nearshore Gulf Of Maine, Kathleen M. Reardon, Carl J. Wilson, Patrick M. Gillevet, Masoumeh Sikaroodi, Jeffrey D. Shields
VIMS Articles
Epizootic shell disease (ESD) is a significant concern to the southern New England lobster fishery. Although ESD has been reported in the southern Gulf of Maine off Massachusetts, there are few reports from Maine waters. We report on the occurrence and distribution of ESD in American lobsters from nearshore Gulf of Maine from the Maine Commercial Lobster Sea Sampling Program. Overall, average prevalence levels of ESD by trip were very low (<0.16%) through 2010, then increased from 2011 to the present, reaching 1.2% in 2013. As with previous studies, recent prevalence levels in legal and sublegal (<127 mm CL) animals were higher (6%–7%) in egg-bearing females than in males and non-ovigerous females. This pattern was amplified in oversized (>127 mm CL) lobsters, regardless of sex and reproductive state, with much higher prevalence levels (up to 22%). Spatially, prevalence levels of ESD were significantly higher in western …
Laboratory Studies On The Effect Of Temperature On Epizootic Shell Disease In The American Lobster, Homarus Americanus, Britnee N. Barris, Jeffrey D. Shields, Hamish J. Small, Juan Pablo Huchin-Mian, Patricia O'Leary, Et Al
Laboratory Studies On The Effect Of Temperature On Epizootic Shell Disease In The American Lobster, Homarus Americanus, Britnee N. Barris, Jeffrey D. Shields, Hamish J. Small, Juan Pablo Huchin-Mian, Patricia O'Leary, Et Al
VIMS Articles
Epizootic shell disease (ESD) is a persistent threat to the population of American lobsters, Homarus americanus H. Milne-Edwards, 1837, in Long Island Sound and off southern New England, USA. ESD is caused by a bacterial dysbiosis that occurs in association with increased water temperature and exposure to anthropogenic stressors. Temperature is a leading factor driving the severity and incidence of ESD. Our objective was to quantify disease progression and dynamics in relation to host molting and mortality at three rigorously controlled temperatures (6, 12, and 18 °C) over a 5–6-mo period. Lobsters were photographed at various time points and image …
Collection Techniques For The Analyses Of Pathogens In Crustaceans, Jeffrey D. Shields
Collection Techniques For The Analyses Of Pathogens In Crustaceans, Jeffrey D. Shields
VIMS Articles
Outbreaks of diseases have been reported from a number of ecologically or commercially important crustaceans in tropical, temperature, and boreal waters. The etiology of a disease is often unknown prior to these outbreaks and the effect of the pathogen on the host population is poorly understood. Various techniques can be used to collect, identify, and monitor host populations for pathogens. These include classical methods, such as visual or histological assessment, to more refined techniques, such as simple and quantitative polymerase chain reaction assays. The strengths and weaknesses of the different methods are presented as well as some general guidelines for …
New Insight Into The Transmission Dynamics Of The Crustacean Pathogen Hematodinium Perezi (Dinoflagellata) Using A Novel Sentinel Methodology, Jeffrey D. Shields, Juan Pablo Huchin-Mian Huchin-Mian, Pattie A. O’Leary, Hamish J. Small
New Insight Into The Transmission Dynamics Of The Crustacean Pathogen Hematodinium Perezi (Dinoflagellata) Using A Novel Sentinel Methodology, Jeffrey D. Shields, Juan Pablo Huchin-Mian Huchin-Mian, Pattie A. O’Leary, Hamish J. Small
VIMS Articles
Hematodinium perezi causes disease and mortality in several decapod crustaceans along the eastern seaboard and Gulf coast of the USA. The route of transmission of the parasite is unknown, but infections exhibit a sharp seasonal cycle in its primary host, the blue crab Callinectes sapidus, that indicates the possibility of a short transmission period in its life cycle. We developed a sentinel methodology based on the use of naïve, uninfected, early benthic juvenile crabs (instars C1 to C10) to investigate the transmission of H. perezi. Crabs were collected from a non-endemic site, held for a short period for evaluation, and …
Human Indoor Exposure To Airborne Halogenated Flame Retardants: Influence Of Airborne Particle Size, M. J. La Guardia, Erika D. Schreder, Nancy Uding, Robert C. Hale
Human Indoor Exposure To Airborne Halogenated Flame Retardants: Influence Of Airborne Particle Size, M. J. La Guardia, Erika D. Schreder, Nancy Uding, Robert C. Hale
VIMS Articles
Inhalation of halogenated flame-retardants (HFRs) released from consumer products is an important route of exposure. However, not all airborne HFRs are respirable, and thus interact with vascular membranes within the gas exchange (alveolar) region of the lung. HFRs associated with large (> 4 mu m), inhalable airborne particulates are trapped on the mucosal lining of the respiratory tract and then are expelled or swallowed. The latter may contribute to internal exposure via desorption from particles in the digestive tract. Exposures may also be underestimated if personal activities that re-suspend particles into the breathing zone are not taken into account. Here, …