THE WAVE


The little guy above may be barely two inches across, but fiddler crabs like this mate-seeking male are an important if little noticed part of our island ecosystem. This one is a mud fiddler (Uca pugnax) who lives in the creekside mud banks at Seabrook's crabbing dock, waving his immense left claw to attract a female to his burrow. If one approaches, he'll also drum his claw or stamp his legs on the ground to keep her interested. Mating occurs inside the burrow, after which the female emerges in about two weeks to release her eggs into the water.


Fiddler crabs are one of the most common and, if you look for them, most conspicuous inhabitants of the Lowcountry's tidal inlets and intertidal zones. (Two other common types along the Atlantic seaboard are the sand fiddler and the red-jointed fiddler.) They're especially abundant at this time of year, the spring mating season. You'll see them foraging in large groups, emerging between high tides to feed from burrows that can be nearly two-feet in depth.



courtesy NOAA

The male's claw at maturity can account for 65% of its total body weight; and if he loses it in a fight with rival male, another will grow on the opposite side at the next molt and a normal-sized one will replace the lost claw. That smaller claw is used to sift mud and sand for algae, fungus and other organic matter transported to the mouth, the back-and-forth motion as if the animal's playing the fiddle of its larger claw. Once the food's been extracted, the crab will roll the remaining sediment into a ball and leave it at the mouth of its burrow to be carried away in the next high tide.


Because they're constantly sifting soil, fiddlers are considered important for aerating the ground and helping to maintain healthy soil conditions. And they're an important protein source for birds like herons and egrets, mammals such as raccoons and foxes, and even other, larger crabs like blue crabs. Keep an eye out for these diminutive but crucial inhabitants as you enjoy the creeks and tidal inlets of Seabrook, and give them a wave back!



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