Sexual size and shape dimorphism in Salamandra salamandra (Amphibia, Caudata, Salamandridae) from the central Balkans

Abstract

Sexual size dimorphism is one of the key evolutionary features that has been studied in many organisms. On the other hand, sexual shape dimorphism has not been examined as well despite being as important as size dimorphism. Therefore, we analyzed the sexual size and shape dimorphism (SSSD) of Salamandra salamandra from the territory of the central Balkans. In addition, we wanted to reconsider if there is some regularity in the geographical distribution of SSSD in the investigated area. Significant differences in size and shape between the sexes were found for the whole sample and among the analyzed groups. Females were larger than males and had bigger heads, interlimb distances and a parotid gland, while males had bigger tails, forelimbs, hindlimbs, and forefoot and hindfoot length. Our results reveal a strong effect of locality on trait variation. This variation from the general pattern of SSSD is not substantial but still has to be considered.