Sexual size and shape dimorphism in the Wushan salamander, Liua shihi (Liu, 1950) (Urodela: Hynobiidae)

Abstract

Sexual dimorphism in size or shape is widespread in the animal world. Many studies have explored this topic, but few have focused on Asian salamanders. In this study, we analyzed morphometric data of the Wushan salamander Liua shihi, an endemic Chinese salamander, to examine sexual dimorphism in size and shape. We evaluated data sets that included 17 morphometric characteristics of 61 females and 55 males using univariate and multivariate methods. Results show that sexual dimorphism in this species includes not only body size (males have a longer snout-vent length than females), but also shape (females have a longer space between axilla and groin and head size than males, while males have greater limb size). This article discusses the evolution of intersexual dimorphism according to models of ecology, fecundity and sexual selection. We propose that sexual dimorphism of body size can be attributed to sexual selection and local climates, that AGS may contribute to fecundity selection, that head size may be attributed to reproductive roles and ecology, and that limb size may be beneficial for reproductive success. However, most aspects of the reproductive biology, ecology and life history of this species remain unknown. This article fills a gap in the literature on this species and builds a foundation for future research. Research on such species is increasingly important as many species of salamander are becoming threatened or endangered throughout the world.