A sisters’ story: comparative phylogeography and taxonomy of Hierophis viridiflavus and H. gemonensis (Serpentes, Colubridae)

Abstract

We used a multidisciplinary approach to infer the taxonomy and historical biogeography of Hierophis viridiflavus and H. gemonensis, performing molecular analyses of itochondrial (16S, Cyt-b, ND4) and nuclear markers (PRLR), a landmark-based morphometric study and a cytogenetic analysis. Our data distinguished three main groups in the studied species, corresponding to H. gemonensis and to two monophyletic clades (E and W) within H. viridiflavus. Clades E and W display a significant genetic (about 4% for Cyt-b and ND4) and morphological divergence and a different morphology of the W sex chromosome (submetacentric in clade E and telocentric in clade W). Taking into account the existing divergence, these clades appear to represent independent phylogenetic units, deserving elevation to species status. Specific names should be H. viridiflavus (Lacepede, 1789) and H. carbonarius (Bonaparte 1833) for cladesWand E, respectively. The phylogeography of the studied species is only partially concordant with a general pattern of ‘southern richness and northern purity’ of genetic diversity, whereas H. gemonensis exhibits high genetic diversity at low latitudes (especially in the Peloponnese), H. carbonarius shows a number of different haplotypes both at low (along the Southern Italian Apennines and in Sicily) and high latitudes in Italy. Furthermore, a relaxed clock model hypothesizes the differentiation between H. gemonensis and H. viridiflavus sensu lato at about 7 Mya, in the Messinian. Subsequently, the speciation involving H. viridiflavus sensu stricto and H. carbonarius took place in the Quaternary, probably as a result of Pleistocene climatic oscillations. Furthermore, our results are consistent with the existence of several ‘refugia within refugia’ in Italy and in the Balkans and depict the major cladogenesis as allopatric events, mainly driven by paleoclimatic and geographical factors

Comparative analysis based on replication banding reveals the mechanism responsible for the difference in the karyotype constitution of treefrogs Ololygon and Scinax (Arboranae, Hylidae, Scinaxinae)

“…Similar integrative taxonomic approach was carried out by Lourenço et al (2015) for amphibians and Mezzasalma et al (2015) for reptiles. As already pointed out by Cardozo et al (2011) and subsequently confirmed in other works, the species of Ololygon (the former Scinax catharinae clade) have NORs in chromosome pair 6, whereas the species of Scinax (the former Scinax ruber clade) generally have this marker in the chromosome pair 11, which also indicates the conservation of this character to cytogenetically differentiate species of both groups.…”

Comparative analysis based on replication banding reveals the mechanism responsible for the difference in the karyotype constitution of treefrogs Ololygon and Scinax (Arboranae, Hylidae, Scinaxinae)

“…Similar integrative taxonomic approach was carried out by Lourenço et al (2015) for amphibians and Mezzasalma et al (2015) for reptiles. As already pointed out by Cardozo et al (2011) and subsequently confirmed in other works, the species of Ololygon (the former Scinax catharinae clade) have NORs in chromosome pair 6, whereas the species of Scinax (the former Scinax ruber clade) generally have this marker in the chromosome pair 11, which also indicates the conservation of this character to cytogenetically differentiate species of both groups.…”

Lifting the curtain on the freshwater mussel diversity of the Italian Peninsula and Croatian Adriatic coast

“…Araujo et al 2005Araujo et al , 2009Froufe et al 2014Froufe et al , 2016a, recent studies have evidenced patterns of population genetic differentiation that could also be explained by the occurrence of this scenario in Italy (e.g. ; Giovannotti et al 2010;Bogdanowicz et al 2015;Mezzasalma et al 2015). In this context, we aim to provide information for the conservation of freshwater mussels in the Italian Peninsula and Croatian Adriatic coast.…”