Family Corbiculidae

Status: 

Our only representative of the family Corbiculidae is the invasive species Corbicula fluminea (Muller, 1774), the asiatic clam. Although widely distributed in the US, C. fluminea is limited in the NY metro area to several lakes on Long Island, NY, and to Twin Lakes, CT, and in NJ is present in all major waterways outside the Pine Barrens.

Species Summaries

Corbicula fluminea (Muller, 1774)
asiatic clam

Features:

size: 50mm, though typically smaller
beak: situated centrally, and highly placed above the hinge line
color patterns: distinguished by three brown or purple radial color bands near the umbos; periostracum brown or blackish brown; nacre colored white and purple
shape: inflated, triangular, or rounded triangular in older specimens
shell features: posterior external hinge ligament, with many coarse concentric ribs on epidermis
teeth: long, finely serrated laterals, two in the right valve and one in the left; pseudocardinals short, strong, with blunt surfaces, three per valve

Status:

abundance: uncommon
status: reportedly in decline; US, NY, NJ, CT: not legally protected
conservation challenges: presence of this invasive species should be sought in New Jersey and Connecticut

Distribution:

N.A. distribution: nearly all major eastern and midwestern river systems; Connecticut west to Minnesota and Iowa, south to Georgia, Oklahoma and Louisiana
present metro distribution: confined to several lakes on Long Island, NY
regional distribution: NY: all major watersheds except the upper Delaware River watershed; NJ: all major watersheds outside the Pine Barrens; CT: Connecticut, Housatonic, Thames River and South central coast watersheds; East Twin Lakes (Housatonic River watershed)

Life History:

habitat: large rivers, canals and lakes on any hard substrate; some tolerance to salinity; limited tolerance to low calcium and acidity Habitat Photo
hosts: no host required; free-swimming veliger larvae

Plates

C. fluminea

Left view	right view
ventral view	profile view
nacre with bluish cast	long, fine laterals; 2 right, 1 left pseudocardinals short, 3 per valve
many concentric ribs