Mole Crabs: Can You Dig 'em? 



Imagine spending your 

 lifetime tumbling and 

 scurrying about in a surge of 

 sand and water. 



Now you know how a 

 mole crab feels. 



As waves crash onto the 

 beach and retreat, the egg- 

 shaped crab pops out of the 

 swash, races to a new spot 

 and digs in the wet sand as a 

 new wave breaks. 



Watching this over and 

 over again, you might think 

 the mole crab a hapless 

 creature. But this tiny 

 crustacean is actually well- 

 suited to its unstable home. 



One of the few creatures 

 that can survive in the surf 

 zone, the mole crab adapts 

 beautifully to its rumble- 

 tumble life. Having no claws 

 or pinchers, the crabs use 

 feathery antennae on their 

 heads to sift food from the 

 water. 



Its powerful legs help the 

 mole crab burrow backward 

 in a hurry. The crab orients 

 itself to the outgoing wave so 

 its antennae can filter 

 plankton — tiny microscopic 

 plants and animals — from 

 the water. 



You may notice a pattern 

 of tiny Vs that remain on the 

 sand as the water retreats 

 from the burrowed crabs. 



Meanwhile, these speedy 

 crustaceans have predators 

 from land, sky and sea. Mole 

 crabs that are too slow make 

 a mouth-watering meal for 



gulls and sandpipers hover- 

 ing over them. 



The crabs are also a tasty 

 treat to fish such as pompano 

 and flounder swimming in 

 shallow waters. That's why 

 experienced fishermen scout 

 out soft-shelled mole crabs to 

 bait their lines. 



Next time you're at the 

 beach, take off your shoes 

 and let the surf lap at your 

 bare toes. You might feel the 

 tiny creatures scurrying 

 around your feet as you 

 wade. 



Scoop up a handful of 

 wet sand and you'll probably 

 catch a few. They may tickle 

 the palms of your hands but 



they can't bite you. 



In the summer months, 

 you may notice bright orange 

 eggs clinging to the bellies of 

 the females. 



Another thing you may 

 notice is how crabs of the 

 same size tend to hang out 

 together at the beach. 



"The big crabs like to 

 stay where the waves are 

 crashing harder, and smaller 

 crabs tend to be farther up 

 the beach where it's calmer," 

 says Lundie Spence, Sea 

 Grant's marine education 

 specialist. 



Scout around, she says, 

 and you should be able to 

 find crabs of all sizes. 



VOCABULARY: 



swash - swift, dashing 

 water. 



crustacean - one class 

 of arthropods that usually live 

 in the water and breathe 

 through gills; they have a 

 hard outer shell and jointed 

 appendages and bodies. 



surf zone - Area of the 

 beach where the waves break 

 and recede. 



antennae - a pair of 

 movable, jointed sense 

 organs on the head of 

 arthropods such as insects, 

 crabs, lobsters, etc. 



— Carta B. Burgess 



14 



