Tetramine Contents in the Salivary Glands from 16 Species of Marine Carnivorous Gastropods Collected along Japanese Coasts

Abstract

Tetramine (tetramethyl ammonium ion), a neurotoxin, is present at high levels in the salivary glands of buccinid gastropods and is responsible for human intoxication due to consumption of the gastropods. We used LC-MS/MS to examine the tetramine contents of salivary glands from 16 species of carnivorous gastropods collected along Japanese coasts. Tetramine was detected in all specimens except for Babylonia japonica. High levels of tetramine were detected in whelks, Neptunea lamellosa (1,380-9,410 μg/g of salivary gland) and N. purpurea (1,190-7,400 μg/g of salivary gland). Although consumption of N. lamellosa is well-known cause of foodborne tetramine poisoning, it was newly discovered that N. purpurea has tetramine. In addition, we found 7 other species of gastropods containing tetramine: Siphonalia cassidariaeformis (117-135 μg/g), S. fusoides (204 μg/g), Buccinum inclytum (2.94-3.40 μg/g), and B. aniwanum (0.700 μg/g) of the family Buccinidae, and Fusinus perplexus (397 μg/g), F. ferrugineus (105 μg/g), and F. forceps salisburyi (67.5 μg/g) of the family Fasciolariidae. The present study, together with previous studies, shows that gastropods with salivary glands containing more than 1,000 μg tetramine/g of salivary gland, including the genus Neptunea as well as Fusitriton oregonesis and Hemifusus tuba, carry a high risk of tetramine poisoning, and their salivary glands should be removed before consumption to prevent food poisoning.