23 described species Arca is a genus of edible saltwater clams in the family Arcidae, the Ark Clams.

[1] 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:[2]