Distinguishing Characteristics |
Carapace oval, narrower posteriorly; anterior lateral margins slightly curved; color greenish brown or greenish blue on carapace, claws white with yellow or orange tinge, mottled brown spots on back of palm; females with very small claws of equal size; males with 1 oversized claw with short tubercle ridge on palm, ridge relatively high, tubercles stop at top of ridge, do not continue to other side of palm; no enlarge tooth or spine on inner surface of carpus (segment next to claw) on enlarged claw in males; palm of male major claw mostly smooth, sometimes with a few small flat tubercles; crest on end of immovable finger of major claw with 3-4 tubercles, the immovable finger is slightly curved inward; walking legs with hairs on dorsal and ventral margins; pile of short bristly hairs (seen with magnification) on the dorsal margin of its 1st 3 walking legs; area between orbits narrow, less than 1/3 of the frontal width of the carapace. |
Similar Species |
Most resembles the Atlantic marsh fiddler, U. pugnax, but the Atlantic marsh fiddler differs in these ways: the immovable finger on the male major claw is straight or with a slight downward curve; the fingers are longer and narrower than the mudflat fiddler; the merus (4th segment from distal end) of the 2nd walking leg is more slender, its dorsal edge straight; ridge on major palm is relatively low, center of palm clearly tubercled, tubercles on palm ridge continue around around carpal cavity to upper side of palm, The red-jointed fidder has red color in the joints of major claw and has no pile of hairs on the dorsal margin of its walking legs; The spined fiddler has straight anterio-lateral margins in its carapace. Other fiddlers may have no tubercled ridge on its inner palm of the major claw. |
Habitat |
Bay, muddy bottoms, above the intertidal zone |
Maximum Size |
2.1 cm (1 in) |
Other Common Names |
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Previous Scientific Names |
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