Portunus pelagicus

Blue swimmer crab
Portunus pelagicus
Portunus pelagicus, Jervis Bay, NSW, Photo: Andrew Green
Portunus pelagicus
Portunus pelagicus, Jervis Bay, NSW, Photo: Andrew Green
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Portunus pelagicus
Portunus pelagicus


Mediterranean, Temperate Australasia, Tropical Indo-Pacific


Long spine projecting from each side of the carapace, the smoothly curved rear of the body and the bluish colouration. Female crabs (known as jennies) are less brightly coloured than males and have a prominent spot at the base of the claws. Blue swimmer crabs are caught in large numbers by professional and recreational fishers. They settle as juveniles in very shallow sandy habitats and grow rapidly, reaching maturity after one year. This crab has reached the Mediterranean in recent times by migrating through the Suez Canal.


Max Size: 21 cm

Sea Temperature Range: 17.2-23.3°C

Depth: 0-60m

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: Infrequent (8.2% 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