Acanthocardia

Acanthocardia is a genus of marine bivalve mollusks in the family Cardiidae. The genus is characterized by its distinctive shell features, including a prominent, spiny ridge along the hinge line, which gives the genus its name, derived from the Greek words "akantha" meaning "thorn" and "kardia" meaning "heart." This genus is found in tropical and subtropical waters around the world, with a few species occurring in temperate regions.

The shells of Acanthocardia are typically heart-shaped, with a smooth or slightly sculptured surface. The hinge is composed of two plates, with the inner plate bearing the characteristic spiny ridge. The outer plate is usually smooth or slightly sculptured. The shells can vary in size, with some species reaching lengths of up to 10 centimeters.

Acanthocardia species are often found buried in sand or mud, with only the hinge and a small portion of the shell exposed. They are filter feeders, using their siphons to draw in water and filter out food particles. The genus is of particular interest to paleontologists, as many species are known from the fossil record, dating back to the Miocene epoch.

There are currently about 15 recognized species in the genus Acanthocardia, with the most well-known being Acanthocardia aculeata, which is found in the Indo-Pacific region. Other species are found in the Atlantic, Pacific, and Indian Oceans. The genus is not considered to be of significant commercial importance, but some species are collected for their shells, which are used in jewelry and decorative items.