Uca pugilator

About: Uca pugilator is a research topic. Over the lifetime, 376 publications have been published within this topic receiving 12303 citations.

How dear is my enemy: Intruder-resident and resident-resident encounters in male sand fiddler crabs (Uca pugilator)

Abstract: Male sand fiddler crabs (Uca pugilator) defend territories that consist of a breeding burrow and a display area where they wave their claw to attract females. Burrow-holding males engage in agonistic contests with both intruding males that attempt burrow take-overs and with other territory-holding neighbors that apparently attempt to limit waving or other surface activities of rivals. Contests employ one or more behavioral elements that range from no claw contact to use of the claw to push, grip, or flip an opponent. We placed each observed element into one of six groups ranked by intensity, which was based on the degree of claw contact and apparent energy expenditure. In the field, contests with intruders began at higher intensity and escalated more rapidly than did those with neighbors. Thus, U. pugilator males exhibit a dear enemy response toward neighbors. However, resident-resident contests increased in intensity when burrows were close, neighbors faced each other when exiting burrows, and neighbors were of similar size. Proximity and orientation determine the ease with which a neighbor may be engaged. Also, neighbors that are close and of similar size pose a greater threat to mating opportunities, favoring heightened intensity of contests.

Molt Staging in the Fiddler Crab Uca Pugilator

Abstract: A rapid molt-staging technique has been developed for the fiddler crab Uca pugilator. Morphological characteristics of setae on the pleopods and the extent of epidermal retraction were used to define the molt stages (A-B, C, D, E) and substages (D0, D1, D2, D3–4) of the fiddler crab. The significance of molt staging as it relates to biochemical and biophysical events is also addressed.

The influence of constant and cyclic acclimation temperatures on the metabolic rates of panopeus herbstii and uca pugilator

Abstract: The comparative influence of acclimation to constant and cyclic temperatures on the metabolic rates of the mud crab, Panopeus herbstii, and the fiddler crab, Uca pugilator, was observed. Although interspecific differences were observed, cyclic acclimation temperatures significantly depressed oxygen consumption in the 15°- 25° C temperature range in both species when compared to rates of animals subjected to constant acclimation rates. Since this depression of metabolic rates occurs over that portion of the yearly temperature range within which the animals are most active, it is suggested that these organisms utilize energy more efficiently when subjected to natural cyclic temperature conditions than when subjected to constant temperature environments. This difference in metabolic data would be significant in analyzing the role of the yearly energy budgets of crabs in ecosystem energetics.

Ecdysteroids and regeneration in the fiddler crab Uca pugilator

Abstract: Regeneration of lost walking legs in the fiddler crab Uca pugilator is divided into three distinct phases—wound healing, basal growth, and proecdysial growth. By means of HPLC/RIA analysis of levels and composition of endogenous ecdysteroid hormones and in vitro assays of 14C-leucine incorporation, we have determined that the transition between anecdysis and proecdysis is the point at which limb bud growth is most affected by ecdysteroids. The growth that occurs during proecdysis is programmed during the anecdysis/proecdysis transition by a small peak of ecdysteroids (Peak I). Early exposure to 20-hydroxyecdysone at this critical window is necessary for further proecdysial growth of limb buds. The later peak of ecdysteroids (Peak II) seen in the hemolymph of these crabs during late proecdysis does not seem to be involved in the regeneration process.