title: Sexual dimorphism and age of Mediterranean salamanders.
abstract: We analysed sexual size dimorphism (SSD) for two Mediterranean species of the "true" salamander clade possessing distinct life histories (Salamandra algira and Mertensiella caucasica) and equilibrated the morphometric approach to individual age by using skeletochronology. For species that have a short breeding season and live at high altitudes, such as Mediterranean amphibians, the fecundity advantage hypothesis predicts female-biased SSD to maximise reproductive success. Our results showed no SSD in either species; however, morphometric data indicated a male-biased dimorphism in limb (arm and leg) dimensions in both species when compared to body size. Limb dimorphisms are likely related to the particular mating system, which involves an amplexus during spermatophore transfer. Arm length appeared sexually dimorphic during ontogeny both in viviparous S. algira and oviparous M. caucasica. A review on SSD indicated monomorphy of body size as a common lineage-specific pattern among the "true" salamander clade, but also the common presence of other traits such as sexually dimorphic limb proportions.
authors.affiliation: Institute of Systematic Zoology and Evolutionary Biology with Phyletic Museum, Friedrich Schiller-University Jena, Erbertstraße 1, D-07743 Jena, Germany.
authors.forename: Sandy
authors.initials: S
authors.lastname: Reinhard
authors.affiliation: Institute of Systematic Zoology and Evolutionary Biology with Phyletic Museum, Friedrich Schiller-University Jena, Erbertstraße 1, D-07743 Jena, Germany.
authors.forename: Sandra
authors.initials: S
authors.lastname: Renner
authors.affiliation: Institute of Biochemistry and Biology, University of Potsdam, Karl-Liebknecht-Straße 24-25, D-14476 Potsdam, Germany; Department of Zoology, State Museum of Natural History Stuttgart, Rosenstein 1, D-70191 Stuttgart, Germany. Electronic address: alexander.kupfer@smns-bw.de.
authors.forename: Alexander
authors.initials: A
authors.lastname: Kupfer
mesh_terms: D000367:Age Factors; D000818:Animals; D049628:Body Size / Q000502:physiology; D005260:Female; D008297:Male; D012098:Reproduction / Q000502:physiology; D012727:Sex Characteristics; D014562:Caudata / Q000033:anatomy & histology*
keywords: Amphibia; Life history; Salamanders; Sexual dimorphism; Skeletochronology