cowries

Cowries are a group of marine gastropod mollusks in the family Cypraeidae, notable for their smooth, glossy, often brightly colored shells. The shell is typically oval and compact, with a long, narrow aperture lined with tooth-like dentition on both sides. When alive, the animal’s mantle can extend over the shell, giving it a polished appearance that is retained after the shell is shed or cleaned.

Distribution and habitat

Cowries occur in warm seas worldwide, with particularly high diversity in the Indian Ocean and western Pacific. They inhabit a range of coastal environments, including coral reefs, rocky shores, and seagrass beds, usually in shallow water but some species occur at greater depths. They are largely nocturnal and emerge to feed on a variety of encrusting organisms.

Ecology and behavior

Diet varies by species but often includes algae, sponges, and other sessile organisms. Some species may feed on coral polyps. Cowries typically hide during the day and browse at night, contributing to the balance of the reef or coastal community where they reside.

Reproduction

Most cowries reproduce by laying eggs in gelatinous capsules that hatch into free-swimming larvae. The larvae undergo development before settling as juvenile cowries, which resemble adults.

Human use and conservation

Shell collectors prize cowries for their color, pattern, and smooth surfaces, and cowry shells have been used as currency in parts of Africa and Asia. They remain popular in jewelry and decorative arts. Some species face threats from overcollection and habitat degradation, leading to regional protections; many others remain common. Ongoing collection practices and habitat health influence the status of individual species.