Taxonomic composition and ploidy level among European water frogs (Anura: Ranidae:Pelophylax) in eastern Hungary

Abstract

The western Palaearctic water frogs in the genus Pelophylax comprise several distinct species and three hybridogenetic hybrid forms. In this study, we focus on the Pelophylax esculentus complex, which consists of two sexual species, Pelophylax ridibundus and Pelophylax lessonae, and their hybridogenetic hybrid, Pelophylax esculentus. Specifically, we investigated taxonomic composition and ploidy level of water frogs sampled in three different types of wetland habitats in the Hortob agy National Park (HNP), eastern Hungary. Using variation in serum albumin intron 1 (SAI-1) and 15 microsatellite loci, we detected the presence of all members of the P. esculentus complex in the studied localities. In one locality, all three taxa occurred syntopically, while in others water frog populations consisted of P. ridibundus and P. esculentus exclusively. The genomic composition of the 63 examined hybrid specimens analysed with microsatellites showed the occurrence of diploid genotypes only. We used a population genetics approach (allelic richness, gene diversity, multilocus genotypes and multilocus disequilibrium) to infer the breeding system of water frogs at HNP. Our data indicate that at least in two populations, hybrids form gametes with clonally transmitted P. ridibundus genome and produce a new hybrid generation by mating with P. lessonae.

An extinct vertebrate preserved by its living hybridogenetic descendant

“…In addition, the intronic markers used could yield biased phylogenetic signals due to specific features, like retrotransposons 17 . Given the complex evolutionary history of Western Palearctic water frogs, involving frequent events of hybridization between species 19 , 20 , robust nuclear phylogenies and admixture analyses will require high-throughput genomic data.…”

Body size variation in hybrids among populations of European water frogs (Pelophylax esculentus complex) with different breeding systems

“…Symbols are the same as in fig. 1. 1995; Rybacki and Berger, 2001;Borkin et al, 2002;Borkin et al, 2004;Mikulíček et al, 2015;Herczeg et al, 2017). Regardless of the differences in taxa contribution, at all three sites we found significant male-biased asymmetry in the hybrid sex ratio (table 1).…”

“…An intriguing population is the L-E-R type, very rare in western Europe, where all members of the P. esculentus complex exist together. Although the L-E-R type is widely distributed in eastern Europe (Lada, Borkin and Vinogradov, 1995;Borkin et al, 2002) and was occasionally found in central Europe (Mikulíček et al, 2015;Herczeg et al, 2017), little is known about how hybrids are perpetuated in these populations.…”

Az Egyek-pusztakócsi mocsarak (Hortobágyi Nemzeti Park) kétéltűfaunája

“…A három zöldbékafaj lokális populációs rendszereinek pontos viszonyait célzott, nagy mintaszámú és lefedettségű genetikai vizsgálatokkal lehet csak megállapítani a fajkomplexumra jellemző összetett hibridizációs mechanizmusok miatt (Vitt & Caldwell 2014). Herczeg et al (2016) vizsgálatai alapján az Egyek-pusztakócsi mocsárrendszerre a kis tavibéka és kecskebéka által alkotott "LE" típusú populációs rendszer lehet jellemző, amely egybeesik saját megfigyeléseinkkel. A vizuális módszerekkel (nappali és esti vizuális keresés és kézi hálózás) minden faj esetében találtunk egyedeket.…”