Venus nux

Venus nux is a species of saltwater clam. They are marine bivalve molluscs in the family Veneridae, sometimes known as the venus clams.

Venus nux can reach a size of 30 - 45 mm. The shells are globular, with dense, concentric ribs on the surface.

Right and left valve of the same specimen:

The species is widespread in the Mediterranean Sea and the Atlantic littorals of Portugal and Spain.