Monetaria

Monetaria is a genus of tropical marine gastropod mollusks in the family Cypraeidae, the cowries. Members of this genus are commonly known as money cowries, and many species have glossy, patterned shells that have made them popular with collectors and jewelry makers. The genus has undergone taxonomic revisions, with several species previously classified in broader cowrie groups now placed in Monetaria.

The best-known species is Monetaria moneta, the money cowry, which gave rise to its common name and historical use as currency in parts of the Indian Ocean and East Africa. Other species in the Indo-Pacific are placed in Monetaria as well, contributing to a diverse range of shell morphologies and color patterns across the genus.

Shells of Monetaria are typically smooth, oval to rounded, and highly polished in life. The aperture runs along the underside and is often narrow with denticulate teeth. Coloration and patterns vary by species, ranging from pale yellows and creams to darker browns and purples, frequently with bands, spots, or rings.

Habitat and biology: Monetaria species inhabit warm shallow waters, including coral reefs, rocky substrates, and seagrass beds, from the Red Sea to the western Pacific. They are primarily nocturnal, grazing on algae and encrusting organisms, and they exhibit the characteristic mantle that can extend over the shell, aiding in its glossy appearance.

Human use: The shells have long been collected for decorative purposes, trade, and ornamentation. In some regions, over-collection and habitat degradation can impact local populations, though Monetaria remains a prominent group among cowries for both natural history and shell collecting.