Meeting Abstract

40.6  Wednesday, Jan. 5  Sexual dimorphism of morphology and functional traits of the introduced Asian house gecko (Hemidactylus frenatus) across a latitudinal cline. CAMERON, SF*; ORTIZ-BARRIENTOS, D; WILSON, RW; The University of Queensland skyefc@hotmail.com

Where different phenotypic optima exist between males and females of a species, sexual dimorphism is predicted to evolve. Although many studies have investigated sexual size dimorphism, inter-sexual differences in performance traits have not been frequently studied. Here, we examined the degree of sexual dimorphism in both morphological and performance traits in the introduced Asian house gecko (Hemidactylus frenatus) along a latitudinal cline. Asian house geckos are a highly invasive species that have recently dispersed across Australia, from the tropics to temperate regions. H. frenatus are also highly territorial and frequently engage in intense disputes and physical fights. We found that a significant latitudinal cline existed in the sexual dimorphism of both head size and the thermal performance of bite force in the Asian house gecko. Tropical populations were found to have the greatest degree of sexual dimorphism. The difference between males and females was significantly greater in tropical populations for both head size and bite force than in cooler populations. However, we found no latitudinal cline in running speed. Implications of this latitudinal cline in sexual dimorphism of both morphological and whole-organism performance traits will be discussed.