Dynamics of diarrhetic shellfish toxins from the dinoflagellate Prorocentrum lima in the bay scallop Argopecten irradians

ivalve molluscs can acquire diarrhetic shellfish poisoning (DSP) toxins via ingestion of toxigenic dinoflagellates. The dynamics and metabolic fate of DSP toxins were investigated in the bay scallop, Argopecten irradians, when exposed to cells of the epibenthic dinoflagellate Prorocentrum lima, a known producer of DSP toxins. Toxin parameters determined were uptake and detoxification rates, and anatomical compartmentalization of toxin components. Tissue and algal extracts were analyzed by liquid chromotography-mass spectrometry (LC-MS) and by liquid chromotography with UV detection (LC-UV).;No mortalities occurred and no feeding inhibition was observed for juvenile and adult bay scallops. Clearance rates were similar for scallops exposed to equivalent biovolume cell concentrations of toxigenic P. lima and the non-toxic diatom Thalassiosira weissflogii; however, absorption efficiency of organic matter was significantly lower for P. lima. Examination of scallop fecal ribbons revealed that a significant portion of ingested P. lima cells were capable of survival and cell division following passage through the scallop gut. Although DSP toxin concentrations in bay scallop viscera tissue exceeded commonly accepted regulatory levels (2...