Molluscs generally possess gills that allow gas exchange between the aqueous environment and their circulatory systems. These animals also possess a heart that pumps blood containing hemocyanin as its oxygen-capturing molecule. Hence, this respiratory system is similar to that of vertebrate fish. The respiratory system of gastropods can include either gills or a lung.
molluscs generally possess gills that allow gas exchange between the aqueous environment and their circulatory systems these animals also possess a heart that pumps blood containing hemocyanin as its oxygen-capturing molecule hence this respiratory system is similar to that of vertebrate fish the respiratory system of gastropods can include either gills or a lung