A NEW SCREENING METHOD FOR ANTIFOULING SUBSTANCES AGAINST THE YOUNG MUSSELS MYTILUS-EDULIS GALLOPROVINCIALIS

A new test for antifouling substances against the young blue mussels, Mytilus edulis galloprovincialis was developed. Mussels crawl around and search, using their foot, for a suitable substratum to attach themselves to by byssus threads. Repellent substances applied to the substratum inhibit this behavior, leading to the present assay method which is simple and fast, and allows an evaluation of, not only repellent activity, but also toxicity of samples. This assay method can also be carried out under the conditions closer to natural than those of previous methods, causing less stress to test organisms, The minimum repellent concentration of p-nonylphenol, which is a known repellent, was one order of magnitude lower when evaluated by the present method than that by the ''byssus-thread method'', while cupric sulfate was evaluated similarly by both methods. This method is, therefore, useful for the discovery of nontoxic, antifouling substances from natural sources, including marine organisms.