Ancient Alien Nature’s Nostradamus By HENRY LIVERMAN beachbites The ghost crab, once called a “secretive alien from the ancient depths of the sea” by the American Natural History Museum Journal in 1940, is now found world-wide. But, of the roughly 20 different species, only one, the Atlantic ghost crab, is found on the US East Coast, says local coastal ecologist Andy Wood. Part of the ghost crab’s mystique is its nocturnal nature, it only hurries seaward at night to moisten its breathing gills. The crab spends most of its time underground in a shallow burrow it calls home. There, it stays cool through the hottest hours of the day and coldest months of the winter. Though a cousin to the fiddler crab, the ghost crab is a much more solitary crustacean. When encountering an unfamiliar visitor in its burrow, the crab displays its claws for intimidation, Wood says, and rubs the claws’ striated ridges together, displaying its intent to be left to its hermetic ways. Though mysterious and entertaining, ghost crabs serve an important purpose in the local ecosystem. They have few natural predators or competition for sustenance in their food chain. This, paired with a flexible diet, Wood says, is what makes them top predators in their environment. “The generalist diet and their specific adaptation to living in and around a very dynamic, open beach environment … by burrowing … are the big keys to their success,” Wood says. The ghost crab is also important as an indicator species. In its food chain, the ghost crab can prey on almost anything it wants. So if something is wrong with any of the chain’s links, it shows in the ghost crab. This means the health and stability of the ghost An alert ghost crab surveys its beach territory with the aid of large eyes that are keenly adapted to detect movement of potential prey, and shadows of potential predators, including herons and foxes. ANDY WOOD 20 WBM august 2014
2014-8
To see the actual publication please follow the link above