Little Heart Shells of the Carditidae Family

Three Little  Heart Shells of the Carditidae  Family can be found in this website:

Phylogeny: Little Heart Shells of the Carditidae Family are bivalve mollusks in the order Carditida. The Carditida order is divided into two superfamilies – Carditoidea and Crassatelloidea. The Carditidae Family is one of two families in the superfamily Carditoidea. The Carditidae Family is a very large family. It is comprised of seven subfamilies, thirty-nine genera, and two hundred twenty-three species. Shells in this family are also commonly called False-cockles.

Description: Little Heart Shells are inflated in profile and may be ovate, quadrate, or trapezoidal in outline. They are equivalve (both valves of equal size and shape). They are generally sculpted with strong radial ribs, though some also have commarginal ridges. The hinge is long and has two or three cardinal teeth. The interior is smooth except for crenulations at the margin, which correspond to the radial ribs. Most Little Heart Shells are white, often with various brown, gray, yellow, orange, red, or purple markings.  Many species have a dark periostracum, which is often hairy. Shells in this family are small to medium in size, with the largest species reaching 11 cm (4.3 inches) in length.

Habitat and Distribution: Little Heart Shells may be found shallowly buried in sand or coarse sediments, or attached to rocks with byssus. They live in the intertidal zone and to depths exceeding 800 m (2,600 feet). They are found worldwide in polar to tropical waters. At least eleven species from this family are found in Mexican waters.

Natural History: Little Heart Shells are suspension feeders that filter plankton and fine detritus from the surrounding water. In turn they are preyed upon by birds, crabs, carnivorous mollusks, sharks, and rays. They are gonochoric and reproduce sexually, with internal fertilization. The females of many species brood their young in incubatory chambers near their gills. Shells in the Carditidae Family are edible are harvested by artisan and small scale fisheries. The shells are often used in shell crafts to make decorative items.