An enormous specimen, weighing up to 5kg (11lbs), with a body length of up to 40cm (16in) and a leg span of one metre (3.3ft), the Birgus latro is the world’s largest terrestrial arthropod. The coconut crab is so-named due to its ability to climb palm trees and break into coconuts with its pincers.
The coconut crab, which can live for up to 30 years, mainly inhabits the forested coastal areas of the islands of the South Pacific and Indian Oceans. A mostly nocturnal crustacean, it hides during the day in underground burrows.
Although coconut crabs mate on dry land, as soon as the eggs are ready to hatch the female releases them into the ocean. Once hatched, the young will visit the ocean floor in search of a shell before coming back to dry land. Once ashore, the coconut crab permanently adapts to life on the land – so much so that it would drown in water because it has developed branchiostegal lungs and special gills more suited to taking oxygen from the air than from water.
The fact that the coconut crab spawns at sea is the main reason for its widespread distribution as currents carry the larvae far afield. Still, the coconut crab remains an endangered species because it is considered a delicacy and is collected as food.