Comparative effects of the toxic dinoflagellate, Karenia brevis, on bivalve molluscs from Florida

摘要: The effects of the toxic dinoflagellate, karenia brevis (Wilson clone), on larval survival and development northern quahog (=hard clam, Mercenaria mercenaria), eastern oyster (Crassostrea virginica) bay scallop (Argopecten irradians) were studied in laboratory. K. feeding activities juveniles from these species plus green mussel (Perna viridis) also examined. Finally, adult scallops exposed to for two weeks investigate possible cytotoxic effects. Survival 3-day-old larvae was generally > 85% all shellfish at Karenia densities 100 cells . ml-1 or less, not significantly different between whole lysed culture. At 1,000 ml-1, less culture than both M. mercenaria C. virginica. 7-day-old affected up ml-1. At 5,000 however, reduced 37, 26 19% A. irradians, virginica, respectively. Development virginica protracted ml-1. Clearance rates determined under static flow-through conditions using cultures brevis. most sensitive, exhibiting a 79% reduction clearance rate least responsive, showing 38% same treatments. displayed intermediate responses. Similar results observed during longer (2 day) exposures continuous supply Bay showed significant decline after 24 hr exposure; oysters by this concentration. No mortality any brief exposures. Adult degenerative inflammatory changes digestive gland, including thickness epithelium, increased size tubule lumens hemocytic infiltration. prospect recovery populations Florida may be hampered recurring blooms