Shore crab Carcinus maenas

Probably the commonest crab in Britain, the shore crab is a medium-sized crab which lives amongst rocks and seaweed from mid shore down to beyond the low tide mark. The shore crab has pointed spines around the front of its ‘face’. They are very variable in colour, often green, red or brown.


They feed on detritus and small animals. During the summer breeding season, a male will find a female and grab hold of her until she moults; at which point they are able to mate. Females will carry their eggs around beneath their body for up to 18 weeks before they hatch. The baby crabs float in the sea for several more weeks before they sink to the sea bed as adults.


Width of body: 9cm




Found all around our coasts.

When to see

January – December


  • They have been introduced to many other parts of the world, including Australia, South Africa and California, where it has become an invasive pest

Common name

Shore crab

Species name

Carcinus maenas

IUCN Red List status


When to see in Scotland

January – December

Where to see in Scotland

Scottish Wildlife Trust reserves such as Montrose Basin or Knapdale Forest.

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