Vocabulary

Mollusks - soft-bodied invertebrate animal that is characterized by an internal or external shell, a foot, a mantle, and visceral mass; member of the phylum Mollusca.

Foot - muscular structure in mollusks that usually contains the mouth and other feeding structures.

Mantle- thin, delicate layer of tissue that covers most of a mollusk’s body and secretes the shell when one is present.

Shell - structure in mollusks made by glands in the mantle that secrete calcium carbonate.

Visceral mass - structure in mollusks that contains internal organs.

Radula - in some mollusks, layer of flexible skin with hundreds of tiny teeth used for feeding

Gill - filamentous respiratory structure in an aquatic animal

Open circulatory system- system in which blood does not always travel inside blood vessels

Closed circulatory system- system in which blood always moves inside blood vessels

Nephridium - simple tube shaped excretory organ used to remove ammonia from the blood and release it from the body

Gastropod - mollusk that moves by means of a broad muscular foot located on its ventral side; usually has a one piece shell for protection.

Bivalve - mollusk that lives within a shell made of two sections that are hinged together.

Cephalopod - marine mollusk whose head is attached to its foot, which is divided into tentacles.