Phylum Mollusca
The phylum Mollusca is one of the most diverse group of animals on our planet. It contains many species, over 80,000 in fact. As such, they are a number of different muscular systems for each mollusk in their respective classes. Mollusks today play an important role in the aquatic ecosystems as predators and prey of animals. In the case of humans, mollusks play a role as a source of delicasies. They are at least ten mollusk classes, three of which are Gastropoda, Cephalopda, and Bivalvia.