Sexual dimorphism in size and shape of traits related to locomotion in nine anuran species from Serbia and Montenegro

Abstract

Investigation of sexual dimorphism patterns give us insight in how organisms adapt to fulfill their roles (reproductive, ecological, social) and enhance fitness. We examined sexual size and shape dimorphism in traits related to locomotion of nine anuran species from Serbia and Montenegro (Hyla arborea, Bombina variegata, Bufotes viridis, Rana temporaria, R. graeca, R. dalmatina, Pelophylax kl. esculentus, Pelobates fuscus and P. syriacus). Sexual size dimorphism in studied species ranges from female and male-biased, to absence of dimorphism. Sexual shape dimorphism was most pronounced in the forelimbs while the differences were small or did not exist in the hindlimbs and sacral traits. Males of most species were characterized by longer proximal parts (humerus and radioulna) and shorter distal forelimb parts, while the opposite pattern was observed in females. Also, some cases of significant intersexual shape differences are size-dependent. This indicates that these male traits are under stronger selective pressures to increase relative to body size, which may allow them to outcompete other males. Different types of behaviour can indirectly shape the limb morphology and lead to differences between the sexes. More data on the ecology and natural history of these animals are needed to explore the factors underlying the observed sex differences.