Yessotoxins( YTXs) are marine algal toxins with polycyclic polyethers produced by three species of dinoflagellate and can be accumulated in filter feeding organisms. YTXs were put into the group of diarrhetic shellfish poisoning( DSP),because they often co-existed with okadaic acid( OA) and dinophysistoxins( DTXs) in shellfish.There were the positive results when shellfish were tested with the mouse bioassay method. However,toxicological studies have shown that YTXs can neither induce diarrhea nor inhibit t...