One of the 22 crabs on WAnimals

Malacostracans · Decapoda · Gecarcinidae

Christmas Island Red Crab

Gecarcoidea natalis

Not Evaluated

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

The Christmas Island red crab is a decapod crustacean of the family Gecarcinidae that lives on Christmas Island and on the Cocos Islands. Their migration is one of the wonders of the natural world, since thousands of them travel to the ocean to lay their eggs but must overcome many dangers to reach the shore. Although the yellow crazy ant is decimating the populations, and a way has been found to control the ant on the island, as of 2018 the species has not been assessed by the IUCN.

Size

up to 11.6 cm

Diet

Detritivore

Feeds on dead organic matter as it decomposes.

Social structure

Solitary

Lives and hunts alone, joining others only to breed.

Sighting difficulty

Unknown

Fun facts

  • GeneralEvery year 50 million crabs cross the island together to spawn in the sea.
  • Its annual migration is one of the great natural spectacles on the planet: tens of millions of crabs leave their burrows at once as the wet season begins and march to the coast, closing roads and carpeting the ground.
  • They do not head for the nearest shore: most make for the island's north-west coast, and they do so in a straight line. The record for a single day is 1,460 metres.
  • The moon sets the timetable: egg-laden females release them into the sea on the exact night of the last quarter.
  • A radio-tracking census estimated 43.7 million adults on the island.
  • Its ecological role is central: they break down leaf litter and disperse seeds. The yellow crazy ant, introduced by accident, has killed between 10 and 15 million of them.

Life cycle & biology

Skeleton type
Invertebrate - articulated calcareous exoskeleton (crustacean)
Habitat & environment
Island rainforest and coasts
Sexual maturity
Reaches maturity at four or five years old
Litter / clutch size
Up to 100,000 eggs per female

Sources consulted: https://es.wikipedia.org/wiki/Gecarcoidea_natalis

Where to watch it

Parks and dive sites where this species has been documented.

Related species

Other species in the catalogue with the most in common with Christmas Island Red Crab — same habitat, park, country, tags or family.

Keep exploring

Based on what we already know about christmas island red crab.

Comments

Share an experience, a fun fact or a tip for seeing the christmas island red crab.

Be the first to comment.