37 research outputs found

    Synopsis of biological data on the pink shrimp, Pandalus borealis Kroyer, 1838

    Get PDF
    This synopsis of the literature was designed to summarize the biological and biochemical studies involving Pandalus borealis as well as to provide a summary of the literature regarding the fisheries data published before early 1984. Included are many unpublished observations, drawn from studies at the State of Maine Department of Marine Resources Laboratory in West Boothbay Harbor, Maine. (PDF file contains 63 pages.

    Combined effects of a parasite, QPX, and the harmful-alga, Prorocentrum minimum on northern quahogs, Mercenaria mercenaria

    Get PDF
    Northern quahogs, Mercenaria mercenaria (L.), frequently are infected with the parasite Quahog Parasite Unknown (QPX, Labyrintohomorpha, Thraustochytriales), which can cause morbidity and mortality of the quahogs. Possible interactions between this parasitic disease and exposure to the harmful dinoflagellate Prorocentrum minimum in M. mercenaria were studied experimentally. Quahogs from Massachusetts with variable intensity of QPX infection were exposed, under controlled laboratory conditions, to cultured P. minimum added to the natural plankton at a cell density equivalent to a natural bloom. After 5 days of exposure, individual clams were diagnosed histologically to assess prevalence and intensity of parasitic infection, as well as other pathological conditions. Further, cellular defense status of clams was evaluated by analyzing hemocyte parameters (morphological and functional) using flow-cytometry. Exposure of quahogs to P. minimum resulted in: a lower percentage of phagocytic hemocytes, higher production of reactive oxygen species (ROS), larger hemocyte size, more-numerous hemocytic aggregates, and increased numbers of hemocytes in gills accompanied by vacuolation and hyperplasia of the water-tubular epithelial cells of the gills. Quahogs had a low prevalence of QPX; by chance, the parasite was present only in quahogs exposed to P. minimum. Thus, the effect of QPX alone on the hemocyte parameters of quahogs could not be assessed in this experiment, but it was possible to assess different responses of infected versus non-infected quahogs to P. minimum. QPX-infected quahogs exposed to P. minimum had repressed percentage of phagocytic hemocytes, consistent with immuno-modulating effect of P. minimum upon several molluscan species, as well as smaller hemocytes and increased hemocyte infiltration throughout the soft tissues. This experiment demonstrates the importance of considering interactive effects of different factors on the immunology and histopathology of bivalve shellfish, and highlights the importance of considering the presence of parasites when bivalves are subjected to harmful-algal blooms

    Characterization of Pfiesteria Ichthyocidal Activity

    Get PDF
    Letter to the Editor regarding article: Drgon, T., et al. 2005. Characterization of ichthyocidal activity of Pfiesteria piscicida: Dependence on the dinospore cell density. Appl. Environ. Microbiol. 71:519–52

    Harmful algal blooms in coastal waters: options for prevention, control and mitigation

    Get PDF
    This report is the product of a panel of experts in the science of blooms of unicellular marine algae which can cause mass mortalities in a variety of marine organisms and cause illness and even death in humans who consume contaminated seafood. These phenomena are collectively termed harmful algal blooms or HABs for short. As a counterpart to recent assessments of the priorities for scientific research to understand the causes and behavior of HABs, this assessment addressed the management options for reducing their incidence and extent (prevention), actions that can quell or contain blooms (control), and steps to reduce the losses of resources or economic values and minimize human health risks (mitigation). This assessment is limited to an appraisal of scientific understanding, but also reflects consideration of information and perspectives provided by regional experts, agency managers and user constituencies during three regional meetings. The panel convened these meetings during the latter half of 1996 to solicit information and opinions from scientific experts, agency managers and user constituencies in Texas, Washington, and Florida. The panel's assessment limited its attention to those HABs that result in neurotoxic shellfish poisoning, paralytic shellfish poisoning, brown tides, amnesic shellfish poisoning, and aquaculture fish kills. This covers most, but certainly not all, HAB problems in the U.S

    Scallops : biology, ecology and aquaculture/ Edit.: Sandra E. Shumway

    No full text
    xx, 1095 hal.: ill, tab.; 27 cm

    Impacts of Harmful Algal Blooms on physiological and cellular processes of bivalve molluscs

    No full text
    Hurmful algal blooms (HABs) are increasingly recognized as having profound effects upon economics of fisheries and aquaculture. Further, HABs are included in a list of concerns about changes in marine ecosystems that increase impacts of diseases and parasites on important resource species and the food webs that support them. This research assessed the interactions between HABs and bivalve molluscs. A number of specific HAB-bivalve interactions were studied, measuring fundamental physiological processes such as clearance and filtration rates of bivalves when exposed to pure cultures of HAB species or mixed benign and HAB cultures. Results indicate that clearance and filtration rates, as well as biodeposit production, were species specific. Further studies demonstrated the presence of intact HAB cells in the biodeposits with the ability to recover, suggesting potential risks for bivalves to be vectors of introduction of HABs into new environments. A simple method for mitigating this risk was demonstrated : keeping shellfish out of mater for 24 hr, or depurating at least 24 hr in quarantined seawater renders cells non-viable. Physiological responses of bivalve molluscs to HABs varied according to the algal/mollusc combination. This study further investigated whether these physiologicalRENNES-Agrocampus-CRD (352382323) / SudocRENNES-Agrocampus-Bibl. Linné (352382308) / SudocSudocFranceF
    corecore