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: Seagrass, Soft sediment

• IUCN Threat Status: Not Evaluated
• Occurrence: Frequent (15% 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.