RESPIRATORY METABOLISM OF THE AMPHYBIOUS MOLLUSC Pomacea lineata (SPIX, 1827): INFLUENCE OF ALIMENTARY CONDITION ON THE OXYGEN CONSUMPTION OF WHOLE ANIMAL AND ITS RADULAR MUSCLE

Abstract

The present work aimed to investigate the respiratory metabolism of the amphibious gastropoda Pomacea lineata, and to measure the oxygen-consumption of both whole animal and its radular muscle in different alimentary conditions (whether fed or starved). The species is interesting in a physioecologic aspect, because it is an important snail as a bioindicator of ecosystem quality. It was observed that respiratory metabolism obtained from respiratory rate variation was significantly reduced (P< 0,05) under starvation effect in the whole animals (0,473 in whether fed and 0,317 in starved), as well as in the respective radular muscles (0,884 in whether fed and 0,521 in starved). The respiratory rate average of the radular muscles was significantly greater (P<0,05) than respiratory rate average of the whole animals (whether fed and starved) as a result of the myoglobin quantity from these muscles. These results are in accordance with the morphofunctional characteristics of P. lineata. Its radular muscle works out actively for getting feed and constitutes the animal scraping bucal organ . This muscle needs enormous quantity of oxygen obtained from water or air environment, in order to justify the important role played for these amphibious gastropoda as a bioindicator of ecosystem quality.