Cypraea annulus, from the South Pacific, is one of the cowries, inhabiting coral and rocky reefs. It is restricted to intertidal areas. In cowries, when the animal is active the mantle comes out and covers the dorsal shell. It adds patterns for camouflage, sensory surface for protection, and probably aids in respiration. Note the prominent incurrent siphon.


bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.


animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature