Methods We digitized the ranges of fiddler crabs (Decapoda, Ocypodidae, genus Uca) and calculated standing diversity as a function of latitude in the Indowest-Pacific, eastern-Pacific Americas and western Atlantic regions. We examined correlations between diversity and summer sea surface temperature, water column primary productivity, and also investigated the contribution of spatial autocorrel...

A foraging fiddler crab can estimate how close a potential intruder is from its burrow entrance, even when the entrance in the sand is invisible to the crab. Recent work shows that, to assess this depth interval, crabs combine information from vision and path integration in an unusual manner.

* To whom correspondence and reprint requests should be addressed. Some crabs (and other crustaceans) build structures (pillars, hoods, chimneys, etc.) next to their burrows (Powers and Bliss 1983). Some of these structures have been shown to function for sexual attraction, e.g., pillars (Uca: Christy 1988a b), hoods (Uca: Zucker 1974 1981, Christy et al. 2002 2003), mudballs (Uca: Oliveira et ...

Chimneys are mud mounds built by fiddler crabs that encircle the entrance to their burrow. Their function in many species is unknown. In Uca capricornis, crabs of both sexes and all sizes build chimneys, but females do so disproportionately more often. There are no differences in the immediate physical or social environments between crabs with and without a chimney. Chimney owners spend less ti...

Fiddler crabs are highly sexually dimorphic. Males possess one small (minor) feeding claw and one greatly enlarged (major) claw; females possess two small claws. The major claw is used to attract mates and for burrow defense, but it is costly for the male to possess. We tested the hypothesis that the major claw also functions as a thermoregulatory structure, a function that would allow males to...

1. Sexually selected structures with dual function of combat and display are likely to be honest signals of male quality to opponents and mates, but should be costly to produce and maintain. 2. Male fiddler crabs use a single greatly enlarged claw as both a weapon in agonistic contests with other males and an ornament to attract females for mating. Given the extreme size of this structure (up t...

Using crab-like dummies, we have shown previously that fiddler crabs [Uca vomeris (McNeill)] defend their burrows against intruders in a burrow-centred frame of reference. The crabs respond whenever an intruder approaches to within a certain distance of the burrow entrance, and this distance is independent of the approach direction. We show here that the crabs combine information from the path ...

The influence of mangrove saplings (Avicennia marina) and fiddler crabs (Uca vocans) on carbon, iron, and sulfur biogeochemistry in mangrove sediment was studied using outdoor mesocosms with and without plants (21 m22) and crabs (68 m22). Saplings grew more leaves and pneumatophores in the presence of crabs. Dense microalgal mats lead to two to six times higher benthic production and about two ...

Fiddler crab females have two small feeding claws while males have only one the other is enlarged and used as a weapon as well as a mate attraction signal. The study was conducted on the small intertidal fiddler crab Uca sindensis in the Abi estuary near Bandar Abbas on the Persian Gulf. Data were collected from September 2007 to August 2008 in order to cover a wide range of ecological conditio...