Carcinus maenas (Linnaeus 1758)

The shore crab feeds on invertebrates including worms, molluscs and crustaceans Small molluscs and barnacles are taken by young crabs (2). Breeding peaks in summer, and mating can only take place shortly after the female moults; the male finds a female before she is due to moult, and carries her around underneath his body for a number of days (2). After the moult, copulation occurs. The female creates a cavity by burrowing in the sand; she lays the eggs whilst positioned over this cavity, attaches them to her walking legs and carries them around for several months (2). After hatching, the larvae are planktonic for 2-3 years. They then settle as young crabs, and reach maturity after around a year (2).

No conservation action has been targeted at this species.

The shore crab is one of the commonest crabs on the shore, and anyone who has gone rock-pooling is likely to have encountered one (3). It is usually dark green in colour, although young individuals may have whitish blotches. The carapace is wider than it is long, and the first pair of walking limbs ('pereopods') have pincers (2).

Found on the shore from the high water mark down to depths of around 60 m (4), and can inhabit estuaries (2).

Found around the coasts of Britain and Ireland (4). It is also common around the coasts of north-west Europe (2).

Common and widespread (2).

Not currently threatened.