The circular crab, Atelecyclus rotundatus, is a common animal on coarse and muddy gravel but not often noticed by divers. This is partly to do with the uninteresting ground it usually favours but also because it is small (max. 4cms) and blends in well. It is quite easy to identify due to its circular shape and the mass of fringing hairs round the edges of the body.
North Sea - St. Abbs Marine Reserve