The zebra mussel, Dreissena polymorpha, is a small species of freshwater bivalve mollusc. Its shell has a striped pattern, hence its name. The overall shape of these attractive shells is not dissimilar to that of the more familiar marine mussels found along Britain’s coasts and they live in a similar way, attaching themselves in clumps to stones, weed, or other shells.
Zebra mussels were originally native to southern Russian lakes, but were accidentally introduced to other countries and are now considered an invasive species. In Britain, they were first reported in the 1820s. Today, they are widespread in many Warwickshire waterways and have been known to clog pipes and water treatment plants. Look out for their unusually shaped and patterned shells amongst material dredged from canals and rivers.