Is it that obvious? An integrative multidimensional approach to understanding sexual dimorphism in pygmy marbled newts ( Triturus pygmaeus )

Sexual dimorphism can result from different selective pressures, such as intrasexual competition, sexual selection, or sex‐specific reproductive demands, and can affect morphological, behavioral, and physiological traits, among others. Understanding the levels of sexual dimorphism is thus key to disentangling the mechanisms underlying the life history of a given species. Here we applied a multidimensional framework to analyze sexual dimorphism in the pygmy marbled newt ( Triturus pygmaeus Wolterstorff, 1905), including morphology, behavior, inflammatory response, and age‐related variation. Female newts were larger, likely maximizing their ability to produce eggs, whereas male newts had deeper tails and longer limbs with lighter and more saturated white bands, presumably making them more visible to females. Males were also more active and faster, which can be associated with greater mobility and, consequently, a riskier reproductive strategy. Male newts reached sexual maturity 1 year earlier than females but had similar lifespans. Younger individuals had deeper tails, suggesting that individual fitness could be age‐dependent. Males tended to have a weaker inflammatory response, reflecting an energy trade‐off from the immune system toward the complex courtship display during reproduction. Overall, the various levels of sexual dimorphism observed reflect the different selective pressures each sex is subjected to. By adopting a multidimensional approach, our results contribute to an integrative understanding of the evolution of sexual dimorphism in amphibians, showing how morphological, behavioral, physiological, and life‐history traits can diverge and covary between sexes.