An interesting feature of these crustaceans is their coloration. Ghost crabs on white beaches are white, and on black beaches, they're black. Scientists have experimented with these crabs by placing the white crabs on black sand and black crabs on white sand. And yes, indeed, they were able to change their coloration over a period of time. Anything to help you from seeing a ghost.
Now you see them, now you don't. Ghost crabs, a.k.a. sand crabs, or 'ohiki, belong to the genus Ocypode, which means fast footed, and that they are. A day at the beach wouldn't be the same without them; all that digging and chasing and scuttling is fun to watch and provides a pleasant diversion after a cool dip. We have two species here: the pallid ghost crab and the horn-eyed ghost crab, and both species may occupy the same beach. The horn-eyed prefers to dig its burrows closer to the shoreline, and makes pyramid-shaped piles of sand when excavating. They are the larger of the two species, getting up to three inches across the carapace, and as the name suggests, they have horny stalks on top of the eye. The pallid ghost crab is a messier excavator, digging higher up on the beach and fanning out the sand around their burrows. They are typically an inch across the shell. Ghost crabs have ten legs to help them do all the digging and running, and of course, feeding. These nocturnal predators and scavengers dine on seaweeds, portuguese man-of-war, mole crabs, detritus; pretty much any debris that's edible. They're like a beach clean-up crew. Breathing is done with gills, so they can take a dunking, and they are able to run around on land as long as the gills are kept moist.
An interesting feature of these crustaceans is their coloration. Ghost crabs on white beaches are white, and on black beaches, they're black. Scientists have experimented with these crabs by placing the white crabs on black sand and black crabs on white sand. And yes, indeed, they were able to change their coloration over a period of time. Anything to help you from seeing a ghost.
1 Comment
JoAnn Garrigan
5/6/2022 02:45:12 pm
Mahalo! I enjoy walking the beach and seeing their colonies. I am happy to know more about them.
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