Paralytic Shellfish Poisons of Ormer, Haliotis tuberculata, from Spain

Abstract

Paralytic toxicity in excess of the quarantine limit of 4 mouse unit (MU)/g as paralytic shellfish poisons (PSPs) was detected in ormer, Haliotis tuberoulata, imported from Vigo, Spain, to Japan, between January and April, 1994. The ormer exhibited an unprecedented anatomical distribution of PSP toxicity. The muscular tissues were highly toxic, in comparison with the visceral ones. Most toxic was the foot (highest toxicity, 106MU/g), followed by the epipodium of the foot (30.9MU/g), mouth (33.2MU/g), viscera (15.6MU/g), right shell muscle (8.2MU/g), and digestive gland (3.7MU/g). The toxicity scores of ctenidium markedly varied in specimens (6.4-99.9MU/g).PSPs were extracted from toxic specimens of the ormer with 80% ethanol acidified to pH 3-3.5, and partially purified by chromatography on a Sep-pak C18 cartridge column and ultrafiltration through an Ultrafree CL-LCC. HPLC analysis demonstrated that the ormer toxins apparently comprised members of the saxitoxin (STX) group, such as STX, neoSTX, and decarbamoylSTX (dcSTX). Regardless of the tissue, dcSTX was the major PSP component, which accounted for 83mol% (epipodium of foot) to 97mol% (digestive gland) of all toxin components. Electrospray ionization mass spectral analysis confirmed that the principal toxin component from the Spanish ormer was dcSTX. Neither gonyautoxin group nor C toxins (N-sulfocarbamoyl-11-hydroxysulfate PSP derivatives) appeared in any tissues. No significant individual variation in PSP composition was observed. These results reveal toxification with PSPs of a herbivorous marine gastropod, and suggest a unique metabolism of PSPs in the ormer.