Callista multiradiata
Similar to Callista florida. Callista multiradiata is distinguishable by its more elongate shape and more inflated valves. In addition, C. multiradiata has weaker hinge plates and weaker teeth than C. florida. C. multiradiata also typically has more radial stripes on its exterior than C. florida.
The overall shape is elongate, ovate. The dorso-ventral height is variable. The posterior margin is very weakly pointed, and the anterior and ventral 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, and there may be weak, wide, rounded comarginal ribs, especially on smaller specimens. Larger individuals are likely to have ribs at the anterior only, with the rest of the flank being smooth and glossy. There are no ribs on the lunule; it is lightly impressed, defined by a fine, shallow groove, and extends half the anterior dorsal margin. The umbo is anterior and the beaks also point slightly to the anterior. The escutcheon is not well defined.
The exterior is white. Additional coloration and pattern are highly variable. There may be light brown, dark brown, purple and/or purple-red coloration in the form of tent marks, comarginal stripes and/or radial stripes. The most common pattern is overlaid comarginal and radial stripes. The interior is white in larger specimens, and there may be purple or brown coloration posteriorly, in the muscle scars and/or in the umbonal cavity in smaller specimens.
The ligament is external, extends 1/3 of 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 united 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 (3a, 1, 3b), none of which are bifid. There are two anterior lateral teeth (A1, A3) on the right valve, both of which are partially connected to the anterior cardinal tooth (3a). There is also a fine, weak ridge running parallel to the posterior dorsal margin on the right valve. The anterior and posterior adductor muscle scars are similar in size and shape. The pallial sinus extends to the end of the nymph in length and its deepest point forms an accute angle.