Our two most common species of fiddler, the sand fiddler and the mud fiddler, are so-named because the male crab sports one very large claw and one small claw reminiscent of a fiddle player. An adult male sand fiddler, Uca pugilator, stands near a burrow while waving the enlarged claw that gives this saltmarsh crab its common name. Fiddler crabs often travel and feed in large groups; a safety-in-numbers strategy that provides lots of watchful eyes to stay on the lookout for predators, including wading birds, raccoons and maybe a person with a net and bucket. 39 www.wrightsvillebeachmagazine.com WBM Visiting a saltmarsh habitat during any warm month will likely include seeing a group, or cast, of fiddler crabs scurrying from one’s approach. If herded into the water, it is quite likely some will end up being grabbed by a blue crab lurking in the shallows. Our two most common species of fiddler, the sand fiddler, Uca pugilator, and the mud fiddler, Uca pugnax, are so-named because the male crab sports one very large claw and one small claw reminiscent of a fiddle player. Female fiddler crabs bear two small claws of equal size, giving her a two-fisted feeding advantage over the awkwardly equipped males. The male fiddler’s large claw is waved about to intimidate other males or to attract the attention of an egg-laden female. On occasion, one may see a large male fid-dler grappling mightily with a smaller male, though rarely does their altercation come to real blows. As their common names imply, the tan and lavender-colored sand fiddler is mostly found in and around the sandy backsides of barrier islands where dunes fan into tidal marsh. Mud fiddlers are brown and burgundy colored, which helps them blend with the muddy banks of tidal creeks and adjacent cordgrass marshes. Watching a fiddler feeding on a mudflat, one can observe it gather a fistful of sand into its mouth, along with bits of detritus, microscopic plants, or diatoms, and other organic matter accumulated as a thin film on marsh surfaces. Once in its mouth, the crab rinses good stuff from indigestible minerals before spitting out a BB-sized pellet of clean sand, thousands of which can be seen scattered over exposed low tide mud and sand flats. The fiddler’s feeding pellets may be found among marble-sized dollops of sand and mud — creations made by fiddler crabs that excavated a burrow in the mud, the crab’s shelter during high tide when flooding seawater draws a host of fiddler predators, including vari-ous fishes, wading birds, terrapins and blue crabs. Crabs require very specific living conditions to thrive. Placing a recently captured crab in a bucket of warm water will likely spell doom for the animal if not released quickly. Observing crabs in a bucket is fine, as long as the animal is not exposed for too long. Due to the fact that crabs breathe oxygen from water, they can drown from lack of oxygen in dirty or warm water. Strange as it may sound, it’s best to just barely cover a crab with water so that it can mix air with water as it breathes. To reduce its stress, be sure to safely release the crab where it was found.
2014-8
To see the actual publication please follow the link above