[Toxicity and toxin profile of scavenging and carnivorous gastropods from the coastal waters of Okinawa Prefecture, Japan].

From January to June 2009, a total of 64 gastropod specimens of 15 species were collected from the coastal waters of Okinawa Prefecture, Japan, and examined for toxicity by means of mouse bioassay. Among the specimens tested, 5 species, Nassarius glans, Nassariuscoronatus, Olivaannulata, Oliva concavospira and Zeuxis sp., were toxic. The toxicity scores of N. glans were very high; 39.6-461 MU/g in muscle, and 98.6-189 MU/g in viscera including digestive gland, followed by Zeuxis sp. (12.7 MU/g in whole body), N. coronatus (5.64-11.1 MU/g in whole body), O. annulata (10.8 MU/g in the whole body), O. concavospira (6.65 MU/g in the muscle). Liquid chromatography/mass spectrometry (LC-MS) revealed that the major toxic component was tetrodotoxin (TTX), which accounting for 13-82% of the total toxicity. As for the remaining toxicity in the case of N. glans, 4,9-anhydroTTX, 4-epiTTX and 11-oxoTTX were contributors. Moreover, Niotha albescens showed no toxicity (less than 10 MU/g) in mouse bioassay, but TTX (5.08 MU/g) was detected by LC-MS. Paralytic shellfish poison was not detected in any of the specimens by high-performance liquid chromatography with fluorometric detection (HPLC-FLD).