Question

in animalia-mollusca

wat do u mean by "coelomic cavity is reduced"?

Answer 1

Although, all members of Phylum Mollusca ( Kingdom Animalia) have true coelom, but it is very small in size. Molluscans have open circulatory system in which blood does not flow in blood vessels, so their most of the body cavity is filled by blood, called hoemocoel. Body cavity is only represented by small area around the heart and to the cavities of the organs of reproduction and excretion. Thus, we can say that hoemocoel replaces most of the body cavity of molluscans. This results in reduction in size of coelomic cavity of molluscs.