Barbatia barbata

Barbatia barbata is a species of ark clam, a marine bivalve mollusk in the family Arcidae, the ark clams.

Description
The shell of an adult Barbatia barbata can be as large as 35 - 100 mm. The shape of the shell of this common species is quite variable. Usually it is oblong and flattened, with many radial ribs cut by concentric lines. When alive or fresh dead, the shell has a characteristic hairy dark periostracum (hence the Latin name barbata, meaning "bearded"), covering the entire surface of the shell except for the apical part.

Right and left valve of the same specimen:

Distribution
This ark clam is found along the coasts of the Mediterranean Sea, especially in Greece, Italy and Tunisia.

Habitat
This species lives on rocky or coralligenous (coral-bearing) seabed.