Phylum Mollusca and Its Classification | Coelomates | Zoology

The phylum Mollusca contains over 100,000 species with a variety of body forms and lifestyles. In mollusks, the coelom is reduced and limited to the region around the heart. The Mollusk body first appeared during the Cambrian Period. All mollusks have: 1. A visceral mass containing internal organs, including the digestive tract, paired kidneys, and reproductive organs. 2. A mantle [...]