Malacostracans · Decapoda · Grapsidae

Sally Lightfoot Crab

Grapsus grapsus

Not Evaluated

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

A rock crab of spectacular colouring — red, orange and blue in the adults — that dominates the rocky shores of the American Pacific and the Galápagos Islands. It runs and leaps among the waves with extraordinary agility and eats algae, carrion, eggs and small animals.

Size

5 cm – 8 cm

Diet

Omnivore

Combines animal and plant food depending on availability.

Activity

Diurnal

Active mainly during the day.

Social structure

Solitary

Lives and hunts alone, joining others only to breed.

Sighting difficulty

Unknown

OceanOmnivore Diurnal Solitary Ocean Crustacean

51countries 13parks 19dive sites1same family

Fun facts

biologíaIt changes colour dramatically with age, from the near-black of the juveniles to a striking red, orange and yellow in the adults.
In the Galápagos it picks ticks and parasites off the skin of marine iguanas, which submit to it without stirring.
It can run up wet vertical walls and leap from rock to rock over the water without falling in.
Its English name, Sally Lightfoot, comes from its agility: it runs at extraordinary speed across vertical rock faces and hides in crevices to escape birds.
It leaps from rock to rock, which is unusual in a crab. It seems to do so both to escape and to avoid entering the water or being hit by a wave.
It feeds mainly on algae, which it scrapes off with spoon-tipped claws.
Adults are bright red and juveniles almost black, which camouflages them on the volcanic rock.