European cowrie  (Trivia monacha)

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).