Land crabs

Christmas Island is home to the most remarkable abundance and diversity of land crabs in the world. Their scavenging activities recycle nutrients locked in fallen leaves, the burrowing tills the soil and their grazing on fruit trees and seedlings is an important factor in determining forest composition.

The land crabs have evolved from marine ancestors as shown by their return to the sea for spawning. Apart from the 20 land crabs shown here, over 160 other species have been recorded from the reefs and shallows of Christmas Island.

Crabs are classified in the vast group of animals called arthropods which have a hard external skeleton. Insects are arthropods, as are spiders, scorpions, millipedes and centipedes. Crabs belong in the arthropod division called crustacea.