Sally Lightfoot Crab

• 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.

Habitat and environment

Surf-beaten rocks on the coasts of the American Pacific and the Galápagos

Sources consulted: Baird (1978); Lubchenco et al. (1984); Freire et al. (2014); Animal Diversity Web