Toxicity of Taiwanese gobies

Abstract

Recently, three paralytic food poisoning incidents due to ingestion of the goby Yongeichthys nebulosus occurred in Taiwan. Therefore, intensive investigation of toxic goby was performed from August 1996 to July 1998. More than 300 specimens of 12 species of gobies were collected from 15 locations and examined for toxicity. The specimens of three species of gobies, Y. nebulosus, Prachaeturichtys palynema, and Radigobius caninus, collected from Pingtung, Penghu, Kaohsiung, Miaoli, and Hsinchu were found to be toxic. The most toxic goby was Y. nebulosus, 93% of which were toxic. Specimens collected from Pingtung Prefecture were most toxic, the toxicity was more than 1000 MU/specimen. A seasonal variation of toxicity in Y. nebulosus was found, and the highest toxicity was observed for specimens collected in winter with a value of 4998 MU/specimen. The toxin was partially purified from the methanolic extract of each toxic species by Diaflo YM-1 membrane ultrafiltration and Bio-Gel P-2 column chromatography. High-performance liquid chromatography and electrophoresis analyses indicated that each toxic species contained tetrodotoxin (TTX) and anhydrotetrodotoxin. Among three toxic gobies, P. palynema and R. caninus are first reported to contain TTX.