Topic
Uca pugilator
About: Uca pugilator is a research topic. Over the lifetime, 376 publications have been published within this topic receiving 12303 citations.
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TL;DR: Asymmetries in thoracic and leg muscles that move the single huge major cheliped of male fiddler crabs are compared to their contralateral homologues in nine species of Uca.
Abstract: Asymmetries in thoracic and leg muscles that move the single huge major cheliped of male fiddler crabs are compared to their contralateral homologues in nine species of Uca. In Minuca (U. longisignalis, U. minax, U. pugnax, and U. rapax) and Boboruca (U. thayeri) species, the major side body muscles are twice as large as the minor muscles, with more muscle fibers. Additionally, the individual sarcomeres are exceptionally long, reaching over 20 µm in length. In contrast, in species of the sub-genus Celuca (U. crenulata, U. panacea, U. pugilator, and U. speciosa), while these muscles may be up to six times larger than their contralateral homologues, with fibers nearly twice as long, the sarcomeres are not so hypertrophied.Major muscles in the chela can be 20 times larger than their contralateral homologues. The largest chela muscles also show exceptionally large sarcomeres among Minuca, but not in Celuca.It is shown that sarcomere lengths are inversely correlated with the speed and duration of the courtship...
12 citations
01 Jan 1993
TL;DR: In this article, the authors found that the sand fiddler crabs Uca pugilator displayed an escape response, in which they moved directionally in the onshore direction.
Abstract: When dislocated offshore at their home beach, the sand fiddler crab Uca pugilator displayed an escape response, in which they moved directionally in the onshore direction. This response probably functions for predator avoidance of an area containing predators such as blue crabs. Directional orientation using celestial cues, beach slope, waves, and landmarks were tested. Male crabs correctly oriented in the onshore direction of the home beach in the presence of only celestial cues but were disoriented under cloudy skies. When exposed to slope, crabs moved in the upslope direction with the threshold slope being 3°. In a wave tank, crabs moved in the direction of wave travel. Crabs avoided a simulated landmark which was interpreted as avoidance of an approaching predator. Thus, celestial cues, beach slope, and waves can guide the onshore escape response of this fiddler crab species.
12 citations
TL;DR: The data obtained with 5-HT and DA agonists and antagonists on red pigment translocation in vivo and in vitro, are consistent with their neurotransmitter candidacies in evoking the release of these erythrophorotropic hormones.
12 citations
TL;DR: It is suggested that males cycle between activities in response to strength and condition, and that males with larger, stouter claws are more likely to court at new and full moons, when the number of mating-receptive females peaks.
12 citations
TL;DR: Almost no light or dark adaptation of the retinal pigment resulted from injections of eyestalk extracts treated with α-chymotrypsin which supports the interpretation that these substances are polypeptides of neurosecretory origin.
Abstract: Several concentrations of extracts prepared from the eyestalks of a specimen of Uca pugilator were injected into other U. pugilator individuals. The distal pigment of the eyes first became light adapted and then dark adapted, the whole process lasting 6 h. The mean integrated response for light adaptation increased progressively up to the highest tested extract (3 eyestalk equivalents/dose), but with the darkadapting response the maximal effect was produced by the extract containing 2 eyestalk equivalents/dose. Gel filtration of eyestalk extracts in Sephadex G-50 showed that the fractions associated with greatest light adaptation were also associated with greatest pigment dispersion in the melanophores. Almost no light or dark adaptation of the retinal pigment resulted from injections of eyestalk extracts treated with α-chymotrypsin which supports the interpretation that these substances are polypeptides of neurosecretory origin.
12 citations