Coconut crab

The coconut crab is the largest land-living arthropod in the world. It weighs up to 4.1 kilograms, and its legs can span as much as 90 centimetres from tip to tip. It lives on islands across the Indian and Pacific Oceans, from Zanzibar in the west to the Pitcairn Islands in the east.

It is really a giant hermit crab. Young crabs carry borrowed snail shells, but adults grow a tough shell on their abdomen and leave the shells behind. Their claws are strong, and the crab is listed as Vulnerable by the IUCN. It has disappeared from places with many people, such as mainland Australia and Madagascar.

A crab that breathes air

Adult coconut crabs breathe with special lungs called branchiostegal lungs, and if they stay underwater too long they drown. They have an excellent sense of smell, which developed in a way similar to insects. They live in burrows and have been filmed climbing coconut palms and pandanus trees. Climbing is also an escape route from enemies when they are far from their burrow.

What does it eat?

Despite its name, coconuts are not a major part of its diet. It prefers fleshy fruit, nuts, seeds and the soft inside of fallen trees, and it also eats carrion. Anything left on the ground can be a snack, so it is called the robber crab or palm thief. Mating happens on land, but females go to the sea edge to release eggs. Sea birds eat young crabs.

On the globe

The model lives on a tropical island. Look for the huge claws and the thick-shelled body.