Arca is a genus of saltwater clams in the family Arcidae, the ark clams.
As is typical for ark clams, species in this genus have a long, straight hinge line. Some species in this genus, such as Arca zebra and Arca noae, have a brown-and-white striped pattern. Arca attach themselves to rock with byssal threads which protrude through a gap on the ventral (open) side.
Species within the genus Arca include:[1]
