My sister and I caught this zooplankton using a plankton net at Pescadero State Beach. This is a mytilus. It will become a large mussel. The tongue-like thing is a foot. The mussel uses the foot to move. I am studying mollusks and how they are effected by ocean acidification. I am studying mollusks because the Phylum Mollusca also includes nudibranchs and octopuses, which are my favorite animals.