Callista chione
Edible species.
Edible species.
The overall shape is elongate, ovate. The anterior, ventral and posterior margins are rounded. The anterior dorsal margin is nearly straight, and the posterior dorsal margin is subconvex. The valves are equal in size and shape (equivalve), and there is no gape when they are closed. Sculpture consists of growth lines only. The lunule is elongate and lightly impressed; it is defined by a fine shallow groove and extends half the anterior dorsal margin. The commissural margin may be slightly raised at the center of the lunule, but it does not extend above the flank. The umbo is anterior and the beaks also point slightly anteriorly. The escutcheon is not well defined.
The exterior is tan, and there are typically overlayed light brown comarginal and radial stripes. There may also be darker brown coloration along the stripes near the umbo, fading ventrally. The periostracum is light brown. There may be a red-brown blotch of pigmentation on the lunule. The interior is white.
The ligament is external, extends half the posterior dorsal margin and is supported by nymphal ridges. On the left valve, there are three cardinal teeth (2a, 2b, 4b), none of which are bifid. The anterior (2a) and central (2b) teeth are joined dorsally, forming an inverted "v" shape. The posterior tooth (4b) is fused with the nymph. There is also one anterior lateral tooth (A2) on the left valve. On the right valve, there are three cardinal teeth: the anterior (3a) and central (1) teeth are not bifid, and the posterior tooth (3b) is bifid. There are two anterior lateral teeth (A1, A3) on the right valve, as well as a fine, weak ridge that runs parallel to the posterior dorsal margin. The posterior adductor muscle scar is slightly larger and rounder than the anterior. The pallial sinus is deep and extends to the middle of the nymph in length; the deepest point forms an acute angle.