Atlantic Ribbed Mussel

The ribbed mussel occurs in the coastal waters of salt marsh habitats from the southern Gulf of St. Lawrence in eastern Canada, south along the western Atlantic coast to Florida. In the Gulf of Mexico this species is replaced by the southern ribbed mussel, Geukensia granosissima, and the two species hybridize in southern Florida. The ribbed mussel has been introduced to Texas, Mexico, California, and Venezuela.

Ribbed mussels are dioecious and sexes can only be determined histologically. They reproduce once per year in Connecticut and South Carolina, however in an introduced population in Venezuela two spawning peaks have been observed. Mussels >15 mm are typically reproductive; however, it is not uncommon for mussels up to 35 mm to have no signs of gametogenesis. Their location in the salt marsh plays a role in when they become reproductive because edge ribbed mussels mature at smaller body sizes compared to other mussels. Ribbed mussel larvae return to the marsh during recruitment, and they tend to settle near marsh edges where there are adult ribbed mussels.

Native Americans near the Jamestown settlement manufactured shell beads that were called "rawrenock" in the local Powhatan language. The production process involved grinding broken ribbed mussel shells into disk-shaped beads and drilling a central hole to string the jewelry with. Surviving examples were recovered from the refuse that filled an abandoned well within the James Fort.