Mortality and histopathology in sheepshead minnow (Cyprinodon variegatus) larvae exposed to pectenotoxin-2 and Dinophysis acuminata

International audienceToxic species of the dinoflagellate genus Dinophysis can produce diarrheic toxins including okadaic acid (OA) anddinophysistoxins (DTXs), and the non-diarrheic pectenotoxins (PTXs). Okadaic acid and DTXs cause diarrheicshellfish poisoning (DSP) in human consumers, and also cause cytotoxic, immunotoxic and genotoxic effects in avariety of mollusks and fishes at different life stages in vitro. The possible effects of co-produced PTXs or live cellsof Dinophysis to aquatic organisms, however, are less understood. Effects on an early life stage of sheepsheadminnow (Cyprinodon variegatus), a common finfish in eastern USA estuaries, were evaluated using a 96-h toxicitybioassay. Three-week old larvae were exposed to PTX2 concentrations from 50 to 4000 nM, live Dinophysisacuminata culture (strain DAVA01), live cells resuspended in clean medium or culture filtrate. This D. acuminatastrain produced mainly intracellular PTX2 (≈ 21 pg cel