Zoologger: The Largest Arthropod to prowl the land

Among the beautiful beaches and gigantic waves in Palmyra atoll, just south of Hawaii, a big creature waits his chance to emerge as the sun goes down. The creature is known as the Coconut Crab, species Birgus latro, and it is Earth’s largest land arthropod. The beast’s measurements are shocking with length up to 40 centimeters and a leg span of 90 centimeters. Although most of its other large competitors live in the ocean, the Coconut Crab has adapted a brilliant way of living.

The crabs are born at sea, usually on a new moon, when their mothers release their fertilized eggs. The newborns live in the sea for about a month and then migrate onto land. In order to be able to survive on land, Coconut crabs developed organs called branchiostegal lungs. They are basically gills turned inside out. These specialized organs were developed because their abdomens were allowed to be exposed to air, unlike other hermit crabs.

Their name implies that they feed on coconuts and many other nuts but using their claws to crack open the shell. They often carry a coconut to the top of a tree and drop it in order to crack it open. Occasionally, they steal food from campers, giving them the nickname robber crabs. Mouths are absent in these crabs, instead they have a gastric mill that grinds the nuts so they can be swallowed.

The large crabs have been hunted to their point where they are non-existent on some islands. Trying to make is safe for them to produce is hard due to the fact that the land and sea would both need to be safe. IN the lab, they have had success in all steps of breeding. Much work has to be done before these trials will be done in the wild. They are sure to help the big crab back into the world.

Blog Post Author: Samantha Hill, Section 124-23

Article Citation:
Marshall, Micheal. “Zoologger: The largest arthropod to prowl the land.” Newscientist. 03 March 2010.<http://www.newscientist.com/article/dn18600-zoologger-the-largest-arthropod-to-prowl-the-land.html>