Entoprocta
. Entoprocts, tiny, mosslike invertebrate animals found in shallow waters. Entoprocts have tentacles and oval-shaped bodies, and usually live in branching colonies. Entoprocts lack a true coelom, or body cavity. A slender stalk attaches the body mass, or calyx, to either an inanimate object or another animal. The digestive tract is U-shaped. On the uppermost surface of the calyx are tentacles made of cilia arranged in a circle around the mouth and anus. The movements of the hairlike cilia create currents that sweep tiny animals and suspended particles into the mouth. Entoprocts may live singly but are more often found as colonial groups, with many individuals arising from a single animal through the asexual process of budding. When sexual reproduction occurs, large yolky eggs are brooded in a special cavity within the circle of tentacles. With the exception of one freshwater genus, the entoprocts are exclusively marine. Because of their small size they are difficult to observe without ...