Carcinus maenasCarcinus maenas, Massachusetts, USA, Photo: Graham Edgar
Carcinus maenasCarcinus maenas, Oban, Scotland, Photo: Graham Edgar
Carcinus maenasCarcinus maenas, Massachusetts, USA, Photo: Graham Edgar
1 / 3
Carcinus maenas
Carcinus maenas
Carcinus maenas


Temperate Australasia, Temperate South America, Temperate northern Atlantic


Greenish grey body with three teeth between the eyes and four teeth around the front of the side margin. The hindlegs are less flattened than on almost all other members of the family Portunidae. This species occurs abundantly under stones and in crevices at shallow estuarine sites. It was introduced into Australia from Europe in the 19th century and has also been introduced into North America. The species is an active predator and has probably affected the populations of a number of local animal species.


Max Size: 7 cm

Sea Temperature Range: -0.2-19.6°C

Depth: 0-5m

Habitat Generalization Index: N/A

Also referred to as the SGI (Species Generalisation Index), this describes the habitat niche breadth of the species. Species with values less than 15 are found in a relatively narrow range of reef habitat types (specialists), while those over 25 may be found on most hard substrates within their range (generalists). Learn more here.

Conservation and Rarity

IUCN Status: Not Evaluated

Occurrence: Rare (0.7% of sites)

Occurrence describes how often the species is found on surveys within its distribution. It is calculated as the % of reef sites surveyed by RLS divers across all the ecoregions in which the species has been observed

Abundance: Few (3 per transect)

Abundance is calculated as the average number of individuals recorded per RLS transect, where present.

Edit by: GJ Edgar. 2008. Australian Marine Life. New Holland, Sydney