European cowrie  (Trivia monacha)

Not threatened (2).

The European or spotted cowrie is a marine mollusc that has an egg-shaped glossy shell featuring many transverse ridges with a long, narrow aperture on the underside (2). The upper surface of the shell is usually a reddish brown colour, and has three characteristic spots that allow the species to be identified easily (3). The head, tentacles, foot and body of this mollusc are brightly coloured; they may be red, yellow, green, brown or orange (3).

This cowrie is found around most British coasts (2). It is found as far south as the Mediterranean, and reaches the extreme north of its range in western France and Britain (3).

You can view distribution information for this species at the National Biodiversity Network Gateway.

Found in association with its prey, colonial sea squirts (ascidians) including Botryllus schlosseri and Botylloides leachi (2) on the lower shore and in the sublittoral zone of rocky shores. It may also live in estuaries (3).

This species feeds on sea squirts by biting lumps from the zooids(3). Breeding occurs in late spring and summer. The sexes are separate and fertilisation takes place internally following copulation. Females lay their eggs into sea squirts by biting holes in the colonies and then laying their flask-shaped egg capsules (each containing around 800 eggs) into the hole. After a few weeks the larvae hatch. They are free-swimming and pelagic for around a month (2) and are usually found in coastal waters during the summer (3).

In some parts of the world, large cowrie shells were once used as currency, but this did not occur in Britain. The word cowrie originates from the Hindu and Urdu languages, as cowries are very common in the Indian Ocean (4).

This species is not currently threatened.

Conservation action has not been targeted at this species.

There may be further information about this species available via the National Biodiversity Network Gateway.

For more information see: Fish, J.D. & Fish, S. (1989) A student’s guide to the seashore. Unwin Hyman Ltd., London.