-Animals (Kingdom Animalia)

-Molluscs (Phylum Mollusca)

-Bivalves Class Bivalvia

-Subclass Autobranchia

-Infraclass Pteriomorphia

-Ark Shells and Allies (Order Arcida)

-Arks, Bittersweet Clams and Allies (Superfamily Arcoidea)

-Ark Clams (Family Arcidae)

-Genus Acar

The Ark Clams of the genus Acar are small to medium-sized marine bivalves in the family Arcidae, characterized by their thick, heavy shells with strong radial ribs and a somewhat rectangular to oval outline. Species of Acar typically have inequilateral valves and a straight hinge line bearing numerous small, interlocking teeth—a defining feature of ark clams. These clams inhabit shallow tropical and subtropical seas, commonly living attached to hard substrates such as rocks, coral rubble, or reef surfaces by means of byssal threads. As suspension feeders, they filter plankton and organic particles from the water column.