Malacostracans · Decapoda · Geryonidae

Deep-sea Red Crab

Chaceon affinis

Not Evaluated

It has not yet been assessed against the IUCN criteria. See full glossary

A deep-water crab of the north-eastern Atlantic, found on the slope off the Azores, Madeira and the Canaries. With a reddish carapace and stout legs, it feeds on carrion and bottom-dwelling invertebrates. It is fished with pots set at great depth and its exploitation is regulated because the species grows so slowly.

Size

10 cm – 18 cm

Diet

Carnivore

Feeds mainly on other animals.

Social structure

Solitary

Lives and hunts alone, joining others only to breed.

Sighting difficulty

Unknown

OceanCarnivore Solitary Ocean Crustacean

16countries

Fun facts

Like many animals of the slope, it grows slowly and matures late, so its populations take decades to recover from overfishing.
It lives at depths sunlight never reaches and finds carrion by smell alone.
It belongs to a genus of deep-water red crabs whose taxonomy has been troublesome: until the 1980s almost every species from the eastern Atlantic and the African coast of the Indian Ocean was wrongly identified as Geryon quinquedens, now restricted to the north-west Atlantic.
Identification by morphology remains difficult because of the overlap between species, and since 2019 mitochondrial DNA has been used to tell them apart.
Genetic analysis places it very close to Chaceon maritae, the species of the African coast.
It is the spread of fishing into ever deeper water that has gradually revealed these crabs' global distribution and led to new species being described.