Estudos preliminares sobre os efeitos de baixas concentrações de detergentes aniônicos na formação do bisso em brachidontes solisianus

Abstract

The authors observed the effect of a mixture of three commercial detergents 1:1:1 on 180 samples of the mollusk Brachldontes solisianus Mytilidae, when submitted to a static bioas-say, for seven days. Dúring this period, the water waS aerated by means of an electric air pump. Throug-hout the experiments, the organisms were fed with a culture of algae. The observation of the effects caused by low concentrations of detergent on the byssal activity of these animais indicated that there is a selective influence of these toxic substances, which depends on the animal's size. The behavior of the mollusks is variable, according to the stage of their development and to the concentration of the pollutant in the water. The results lead to the conclusion that the presence of detergents in the water, either biodegradable or not, may cause, even in low concentrations, behavioral changes in the aquatic organisms, particularlly in the mollusks, thus being a factor of negative influence on all aqua-tic communities.