Asiatic Clam

Asiatic Clam or Asian Clam
Asiatic clam

Corbicula fluminea (Mueller)

Description: Shell small (less than 2 inches) round to triangular. Color is yellow in small individuals to black in larger specimens. Juveniles have a dark purple stripe on the umbo that extends ventrally. The beak is located centrally on the dorsal margin. Nacre is white to purple.
Size: Up to 2 inches. Host: Not necessary.
Comment: This is an introduced species from Asia in the mid-1900s and now found throughout Alabama. Densities vary, but may reach several hundred per square meter and may be cyclic with extensive mortality events reported regularly. They can self-fertilize; and Asiatic clams, unlike native mussels, do not use a host.  They release up to 2,000 juveniles per day, and more than 100,000 in a lifetime. Juveniles are only 1 mm long when discharged, and take one to four years to reach maturity. At this time they are about one centimeter long. Adults can reach a length of about 5 cm.