Histological and histochemical alteration in certain Black Sea bivalves submitted to accidental pollution

Due to their microphage capacity, two-valve shells have great biologic importance: they clean the environment of harmful microorganisms and decaying organic compounds which result in water purification, water filtering by means of adaptive structures of digestive system and, indirectly, by those of respiratory, circulatory and excretive system is of major significance. Waste materials derived from animal metabolism coalesce in larger aggregates which sink and deposit onto the bottom, thus enabling the bivalvular shells to contribute to developing and securing adequate conditions for the productive cycle of marine environment and even twining themselves into food for animals. Our study makes a histological, histochemical and histometric survey of branchia (ctenidia) of Mytilus galloprovinciallis so as to enlarge the scant body of knowledge on the topic in reference literature.