Reduced Cuticular Permeability Promotes Inland Habitat Expansion and Freshwater Survival in the Fiddler Crab Uca Minax but not in its Less Terrestrial Counterparts U. Pugilator and U. Pugnax

摘要: We report a two-fold suppression in activation energy for water loss adult Uca minax males compared to co-occurring species, U. pugilator and pugnax, that overlap salt marsh/estuary habitats, implying water-tight cuticular modification is unique minax. This further reflected by drop Arrhenius frequency (steric) factor A as an integrated measure of effectiveness. also distinguished enlarged body size (approximately 5× large the other two species) enhanced capacity retention pronounced 4-5 fold decrease net transpiration rate, presumably result surface area volume properties reduction permeability. High rates correspond high energies suggesting they are more porous; values pugnax were highest indicating this species most prone stress. Features these crab have common 67% content, twice amount their dry mass (size), absence critical transition temperature (CTT) safeguards them against abrupt, lethal loss. Lack CTT agrees with previous descriptions crabs having no water-proofing epicuticular lipids matches rapid limitation wet habitats. The ability conserve restricting loss, however, makes less dependent on moisture-rich habitat, parallels field data account differential thrive terrestrial inland locations resisting desiccation survive fresh being porous entry. Results consistent view placing priority investigating what actually doing (they operate smaller scale; i.e., microhabitat) important application rate than general indicator moisture-requirements species. Une diminution de 2 fois l'energie d'activation pour la perte d'eau chez les adultes d'Uca compares aux deux especes et qui coexistent dans habitats lagunaires estuariens ete observee, impliquant des modifications cuticulaires empecher l'entree d'eau. Ceci est aussi reflete par une chute du facteur frequence d'Arrhenius, en tant que mesure integree l'efficacite cuticule. se distingue par, taille plus grande (approximativement ×5 rapport autres especes) capacite retenir l'eau grâce taux transpiration, probablement consequence proportion d'une permeabilite cuticulaire. Des eleves correspondent energie elevee suggerant ces sont permeables; valeurs etaient elevees, indiquant cette espece sensible au stress aqueux. Les caracteristiques crabes ont commun contenu eau corporelle, leur poids sec (taille) l'absence critique (CTT), ce protege contre brutale letale. L'absence accord avec precedentes ne possedant pas lipides impermeabilisants, rapide restriction humides. La conserver restreignant pertes, le rend cependant moins dependant d'un habitat riche humidite, ceci rejoint donnees terrain indiquent differente prosperer l'interieur terres resistant dessiccation survivre douce etant permeable resultats l'opinion que, placer priorite sur observations (micro-habitats) l'application qu'indicateur exigences d'humidite espece.