The Reproductive Success of Triturus ivanbureschi × T. macedonicus F1 Hybrid Females (Amphibia: Salamandridae)

Abstract

Two large-bodied newt species, Triturus ivanbureschi and T. macedonicus, hybridize in nature across the Balkan Peninsula. Consequences of hybridization upon secondary contact of two species include species displacement and asymmetrical introgression of T. ivanbureschi mtDNA. We set an experimental reciprocal cross of parental species and obtained two genotypes of F1 hybrids (with T. ivanbureschi or T. macedonicus mtDNA). When hybrids attained sexual maturity, they were engaged in mutual crossings and backcrossing with parental species. We followed reproductive traits over two successive years. Our main aim was to explore the reproductive success of F1 females carrying different parental mtDNA. Additionally, we tested for differences in reproductive success within female genotypes depending on the crossing with various male genotypes (hybrids or parental species). Both female genotypes had similar oviposition periods, number of laid eggs and hatched larvae but different body and egg sizes. Overall reproductive success (percentage of egg-laying females and viability of embryos) was similar for both genotypes. The type of crossing led to some differences in reproductive success within female genotypes. The obtained results suggest that processes that led to exclusion of T. macedonicus mtDNA in natural populations may be related to the survival at postembryonic stages of F2 generation or reproductive barriers that emerged in subsequent hybrid generations.

Meeting report: Salamander models in cross‐disciplinary biological research meeting

“…P. waltl provides an interesting alternative to the more commonly used axolotl, due to its shorter generation time and their limited cannibalism. Furthermore, Tijana Vučić (University of Belgrade, Serbia) discussed emerging Triturus newt models which can be bred in captivity and constitute valuable systems for ecological and evolutionary studies, including probing of balance lethal systems 14 . Beyond new models, the meeting benefitted from the introduction of cell resources, including a new method for culturing dorsal root ganglia from axolotls, from Gürkan Öztürk (Medipol University, Turkey), enabling studies of axon formation and regeneration.…”

Changes in thyroid histomorphology and thyroglobulin immunostaining upon exposure to thiourea in Triturus newts

“…These two species hybridize in nature at their contact zone (Arntzen et al, 2014;Wielstra et al, 2017) and hybrids cannot be distinguished based on their external features from their parental species (Arntzen et al, 2018). Subtle differences in life history and morphological traits between hybrids and their parental species are in the range of differences between the two parental species (Bugarčić et al, 2022;Vučić et al, 2019Vučić et al, , 2022.…”