Sexual dimorphism in Trapelus lessonae (De Filippi, 1865) (Sauria: Agamidae) from western Iranian Plateau

We collected 60 adult males and 85 adult females of Trapelus lessonae De Filippi, 1863 in early May 2008 from central Iranian plateau to study sexual dimorphism in morphological traits as well as female reproductive traits. Size-related sexual dimorphism occurred in all the compared body dimensions. The largest female was 83.88 mm in snout-vent length, and the largest male was 73.12 mm. As well, adult males were larger in head size and tail length, whereas females were larger in body size and abdomen length. Males and females also presented differences in color pattern, and in the presence of preanal pores. The results suggest that, in Trapelus lessonae, sexual dimorphism in size is determined by sexual selection, competition between males and fecundity selection, fecundity advantage for large female size. A pattern generated by fecundity advantages enjoyed by large females.