Occurrence of paralytic toxicity in marine flatworms.

Abstract

Assays were made of the paralytic toxicity of marine flatworms. Several hundred specimens of unidentified flatworms, which were classified into “type A” (larger and round) and “type B” (smaller and ellipsoidal) for convenience, were collected from Miura and Izu Peninsulas and the Seto Inland Sea and assayed for toxicity by the official method for tetrodotoxin. Mast of the “type A” specimens assayed were moderately to highly toxic irrespective of the place of collection, the highest toxicity being 1800 MU/g whole body. Some seasonal variation in toxicity was recognized in this type of flatworm. In contrast, most of the “type B” specimens were found to be nontoxic, except for some specimens which showed a toxicity up to 914 MU/g whole body.