Clio

Clio, a genus of shell-less pelagic molluscs in the class of Pteropods. They occur in myriad swarms in northern (C. borealis) and southern (C. australis) seas, and along with such related forms as Limacina form the principal part of the food of some species of whales. The whalers rightly call it 'whales' food.' The whale has simply to swim through a shoal with its mouth open to engulf thousands. Clio is a small animal of a spindle-shape, towards an inch in length, with distinct head, bearing six tentacle-like processes, which are sensitive and glandular, and in part used for laying hold of the prey of small animals. It is active in habit, rising to the surface when calm, or as rapidly sinking again. It swims by means of two locomotor expansions of the 'foot.' See PTEROPODS.