Occurrence of a new toxin and tetrodotoxin in two species of the gastropod mollusk Nassariidae.

The lethalities of 102 specimens of three species of the gastropod mollusk Nassariidae, collected from fish markets in Taiwan, were examined. The frequency of toxicity in Zeuxis scalaris and Z. castus-like specimens was 94 and 41%, respectively. The range of lethal potency in toxic specimens of Zeuxis scalaris and Z. castus-like was 2-140 and 2-13 mouse units, respectively, while all tissues of Z. castus were non-toxic. The toxins were partially purified from the toxic specimens of Z. scalaris and Z. castus-like. Two toxin fractions were obtained from the extract of each species of Nassariidae by using Bio-Gel P-2 column chromatography. Analyses by thin layer chromatography, electrophoresis, high performance liquid chromatography and ultraviolet spectroscopy, showed that toxin fraction I contained tetrodotoxin while toxin fraction II contained a new neurotoxin.