Paralytic shellfish poisoning (PSP) is one of the four recognized syndromes of shellfish poisoning (the others being neurotoxic shellfish poisoning, diarrhetic shellfish poisoning and amnesic shellfish poisoning). All four syndromes share some common features and are primarily associated with bivalve molluscs (such as mussels, clams, oysters and scallops). These shellfish are filter feeders and, therefore, accumulate toxins produced by microscopic algae, such as dinoflagellates and diatoms, and cyanobacteria.[1] Human toxicity and mortality can occur after ingestion of these animals, but toxicity is also seen in wild animal populations.