Evaporative water loss, corporal temperature and the distribution of sympatric fiddler crabs (Uca) from south Texas.

摘要: Desiccation and thermal stress are among the primary factors limiting terrestriality in crustaceans. Water loss was estimated as weight change five sympatric species of Uca from south Texas for periods up to 7 hr dry air. Simultaneously, corporal temperature measured with a thermocouple placed under carapace. To estimate integumental permeability water, 115 mm2 portions dorsal carapace were glued U-shaped tubes containing crab Ringer's solution. These exposed air water change. In whole-animal studies, most rapid occurred first 5 min exposure body fell below ambient (25°C) all species. The three terrestrial exhibited significant survival over more aquatic congeners after prolonged desiccation. greatest rate observed subcylindrica which lost 22.9 ± 3.0% weight. panacea spinicarpa 14.1 1.6% 18.5 1.8%, respectively. Based on blood osmolarity changes, longisignalis rapax resistant than these conditions. sections highest (10.4 mg/hr/cm2) (8.9 mg/hr/cm2). intermediate (4.5 4.2 while expressed lowest value (2.9 observations support notion that can effectively lower fiddler crabs. However, an inverse relationship between not evident congeners. Ultimately balance physiological behavioral mechanisms must be achieved adaptation semi-arid habitats Texas.