Survey of paralytic toxins in shellfish in southern Taiwan between 1995 and 1997.

To establish the safety data of shellfish in southern Taiwan, a total of 3,074 specimens of 30 shellfish species were seasonally collected from August 1995 to March 1997. These samples were assayed for the presence of tetrodotoxin (TTX) and paralytic shellfish poisons (PSP) by the bioassay methods. It was found that some major shellfish including oyster, clam, ear shell, and purple clam were nontoxic, but four species, Babylonia formosae, Niotha clathrata, Natica lineata, and Natica vitellus, were toxic. The toxic percentages of these four species was 1% in B. formosae, 56% in N. clathrata, 37% in N. lineata, and 23% in N. vitellus. The toxic composition was TTX in B. formosae. In the other three shellfish types the toxic composition was TTX and PSP.