Christmas Island Red Crab

During the breeding season, roads can dangerous for cars as well as the crab. Their shells are so hard they can puncture tires.
Christmas Island Red Crab Scientific Classification
Scientific name
Gecarcoidea natalis
Christmas Island Red Crab Physical Characteristics
Red, Orange
About 44 million
20-30 years
17 ounces
Christmas Island Red Crab Distribition

” Below, There and Almost everywhere”

Great deals of animals move, however couple of movements are as astonishing as that of the Christmas Island red crab. Triggered by rains and the stages of the moon, this little animal bestirs itself from its damp burrow and its singular life and marches towards the sea as unstoppably as General Sherman. No person has actually yet determined exactly how a crab’s little mind determine the stages of the moon and exactly how it recognizes the accurate minute, when the stage and the trends are perfect, to launch its eggs. Yet, it does and has actually provided for centuries. The outcome is a phenomenon that captivates the globe and a populace of crabs that remains in the 10s of millions also after crimes by something called the yellow insane ant.

4 Extraordinary Christmas Island Red Crab Realities!

Below are some impressive realities regarding the Christmas Island red crab:

  • The Christmas Island Red Crab is a land crab, however it still takes a breath with its gills and requires to remain wet. It will certainly pass away if it dries.
  • They are native to the island to Christmas Island and CocosIsland Native to the island methods they are normally discovered no place else on the planet.
  • In order to maintain moving crabs from being run over and tires from being pierced, the Australian federal government has actually constructed bridges and passages for the crabs to go across in safety and security. In various other areas, automobiles are merely not enabled to be when driving throughout the crab’s movement.
  • The climate throughout the stormy period is essential to the movement. If it’s as well completely dry, the crabs may wait one more month prior to they venture from the woodland to the shore.

Christmas Island Red Crab Classification and Scientific name

The Christmas Island Red Crab’s scientific name is Gecarcoidea natalis The name originates from the Greek Ge, which suggests “planet,” and carcoid, which has something to do with “crabs.” Natalis is Latin for “birthday celebration” and celebrates Christmas, the birthday celebration of Christ. So the name can equate right into something like “planet crab of the island called for Christ’s birthday celebration.” The crab comes from the Gecarcoidea genus, which includes another species. This is Gecarcoidea lalandii, a purple crab discovered on the Andaman Islands.

Christmas Island Red Crab Species

Gecarcoidea natalis is the only crab in its species. Although a populace has actually been developed on Cocos Island, both populaces are taken into consideration to be of the very same species.


The Christmas Island red crab is taken into consideration a big crab with a covering of virtually 5 inches vast and a weight of a little over an extra pound. The majority of these crabs are a dazzling, eye- capturing red shade, though there have actually been crabs that are extra orange or, hardly ever, purple. The males are larger than the females, however their abdominal areas are narrower.

As the name of its order Decapoda recommends, the crab has 10 legs. There are 8 smaller sized legs, 4 on each side of the covering, and both front legs have actually progressed right into big claws called chelae. Unlike a few other crabs, the chelae of the red crab coincide dimension unless among them has actually been shed and is growing back. Females often tend to have smaller sized chelae than males.

Christmas Island red crab on rocks
The Christmas Island red crab is most popular for its unbelievable yearly movement to the sea. Zinni- Online

Distribution, Populace and Environment

The Christmas Island red crab is discovered just on Christmas and Cocos Islands, which are currently possessed by Australia. Though these islands are fairly tiny, researchers approximate that there are virtually 44 million to 50 million crabs, a lot of discovered onChristmas Island This holds true although an animal called the yellow insane ant is in charge of eliminating countless crabs. This savage ant was mistakenly given the island from west Africa.

The red crab invests a lot of the completely dry period in its burrow in its jungle environment. The atmosphere of the burrow is wet, a needs to for an animal that can moist out. It lives there alone and will certainly repel any type of intruder. In some cases, it will certainly connect up the entryway of its burrow with greenery or dirt. The crab additionally molts in the safety and security of its burrow.

Unlike some fossorial animals, the Christmas Island red crab usages and keeps the very same burrow for as lengthy as 5 years, and the ground cover that’s around the entries develops a beneficial location for plants to sprout. The crab’s droppings additionally give plant food. This is exactly how it adds to its island’s community.

Predators and Target

There are a lot of red crabs that it can not truly be stated that the species has all-natural predators, however it is occasionally taken by the significant coconut crab. Christmas Island red crab children are most in danger for predation. While they belong to the zooplankton in the sea they are consumed by filter feeders such as whale sharks, which time their brows through to the shoreline with the crab’s reproducing period. The little crabs are additionally consumed by all sort of fish and birds.

The yellow insane ant, which is a hostile and intrusive species, has not just eliminated countless grown-up crabs however has actually changed millions extra. Though these ants do not attack or sting, they attack the crab’s burrow and merely bewilder it with sprays of formic acid. When the crab lastly passes away of fatigue, the ants devour it.

Recreation and Life Expectancy

The crab’s reproductive technique has actually interested millions worldwide. At the beginning of the stormy period, the generally singular crab leaves its burrow and go to the sea. It does this although it’s a land crab, for land crabs still require to lay their eggs in water. At some point, countless these crabs make their method necessarily towards the coastlines of Christmas and Cocos Islands. Relying on where the crab survives on the island, this can take around a week.

Males show up initially and dig burrows, and females join them later on. After they mate in the burrow, the male fallen leaves. The female begins generating eggs and maintains them in an unique brood bag on her abdominal area for regarding 2 weeks. After that, prior to dawn, simply when the high trend transforms throughout the moon’s last quarter, she leaves the burrow and trembles her eggs right into the water. Researchers have actually not determined exactly how the female recognizes to launch her eggs at this accurate time.

When the eggs hatch out, the larvae sign up with the clouds of plankton in the sea. If they’re not consumed, it takes regarding a month for them to become little megalopae, after that really little crabs. After that, they leave the water and make their method to the facility of the island. This as well can take a week or longer. They’ll conceal under ground cover, under rocks or tree branches. They will certainly be old sufficient to sign up with the annual movement when they’re 4 or 5 years of ages and can appreciate a life expectancy of 20 to three decades.

Christmas Island Red Crab in Angling and Food Preparation

Regardless of its multitudes, Christmas Island red crabs are ruled out edible, at the very least not edible to humans.


Regardless of the intrusion of the yellow insane ant, the populace of the Christmas Island red crab is counted as around 43.7 million people, and it aids that a female creates approximately 100,000 eggs throughout the reproducing period. The crab’s condition stays of least concern. Among the realities that add to these multitudes is the termination of Maclear’s rat, which made use of to maintain the crab’s numbers in check.


  1. DW, Available here:
  2. Oxford Academic Journal of Crustacean Biology, Available here:
  3. The University of Chicago Press Journals, Available here:
  4. CABI Invasive Species Compendium, Available here:
  5. (1970)

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