Occurrence of tetrodotoxin in three Nassarius gastropod species in Khanh Hoa Province, Vietnam

Abstract

Neurotoxic poisonings with fatal symptoms caused by consumption of Nassarius gastropods have been reported in Vietnam but the causative toxins have not been confirmed. In the present study, Nassarius conoidalis, N. glans and N. pullus, which are considered to be common causative species, were collected in Khanh Hoa province, Vietnam in May 2016 for toxin analysis using LC/MS/MS. The results confirmed that TTX is a dominant toxin in these gastropods. Among them, N. glans exhibited the highest toxicity (412.7 ± 107.3 MU/g), followed by N. conoidalis (144.8 ± 82.0 MU/g) and N. pullus (19.6 ± 9.8 MU/g). This is the first report confirming TTX in these species. All specimens in this study were hightly toxic, indicating that the frequency of toxic specimens of the three Nassarius species is extremely high. Further, their toxicities were all beyond the regulatory level of consumption (10 MU/g) for puffer(fish) as recommended in Japan. The present data indicates that N. conoidalis, N. glans and N. pullus are not suitable for food in Vietnam.