Solenogasters

a class (Aplacophora or Solenogastres) of invertebrate animals of the phylum Mollusca. The body is wormlike (sometimes up to 15 cm in length) and is almost entirely covered by a mantle. Most solenogasters have a longitudinal groove on the ventral side that contains a small ridge, the rudiment of a foot. They do not have shells, and most lack gills. There are about 120 species classified in 26 genera. Solenogasters are extremely common, inhabiting the seas at depths of from 15 m to 4,000 m. They bury themselves in ooze, feeding on detritus, or live on coral or hydroids, on which they feed. The species Chaetoderma nitidulum, with a body length of up to 8 cm, is common in the northern and far eastern seas of the USSR.