Clea sp., a Thai freshwater snail.

Neogastropods can usually be recognized by their long incurrent siphon and accompanying siphonal structure on the base of the shell. Nearly all neogastropods are marine. Clea is a rare freshwater genus.


John B. Burch (author), Mollusk Division, Museum of Zoology, University of Michigan-Ann Arbor.


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