abstract:A paralytic shellfi sh poisoning caused by meat from an unknown scallop occurred in South Taiwan. Scallop meat residue retained by the victim was assayed for toxicity and mitochondrial DNA. The scallop meat toxin was of low concentration and identifi ed by HPLC-FLD as saxitoxin. The 16S rRNA gene sequence of the unknown scallop meat was determined and PCR-RFLP analyses of the meat were completed. When compared with the well-known scallop species Atrina pectinata, Amusium pleuronectes and Mizuhopecten yessoensis, the 16S rRNA gene sequence and PCR-RFLP analyses showed a match with Atrina pectinata. This is the fi rst report in which the scallop Atrina pectinata has been found to contain saxitoxin and to have caused a food poisoning incident. KEY WORDS. – Paralytic shellfi sh poisons, PCR-RFLP, HPLC-FLD.