Until now, five groups of shellfish toxins have been distinguished, namely: paralytic shellfish toxins causing paralytic shellfish poisoning (PSP); diarrhoeic shellfish toxins causing diarrhoeic shellfish poisoning (DSP); amnesic shellfish toxins causing amnesic shellfish poisoning (ASP); neurotoxic shellfish toxins causing neurotoxic shellfish poisoning (NSP); and azaspiraxit shellfish toxins causing azaspiraxit shellfish poisoning (AZP).