Stand out from the Crowd: Small-Scale Genetic Structuring in the Endemic Sicilian Pond Turtle

Luca Vecchioni,Melita Vamberger,Marco Arculeo,Uwe Fritz,Federico Marrone

doi:10.3390/d12090343

Abstract

The geographical pattern of genetic diversity was investigated in the endemic Sicilian pond turtle Emys trinacris across its entire distribution range, using 16 microsatellite loci. Overall, 245 specimens of E. trinacris were studied, showing high polymorphic microsatellite loci, with allele numbers ranging from 7 to 30. STRUCTURE and GENELAND analyses showed a noteworthy, geographically based structuring of the studied populations in five well-characterized clusters, supported by a moderate degree of genetic diversity (FST values between 0.075 and 0.160). Possible explanations for the genetic fragmentation observed are provided, where both natural and human-mediated habitat fragmentation of the Sicilian wetlands played a major role in this process. Finally, some conservation and management suggestions aimed at preventing the loss of genetic variability of the species are briefly reported, stressing the importance of considering the five detected clusters as independent Management Units.

Highlights

The western Palaearctic genus Emys Duméril, 1805 contains two species, Emys orbicularis (Linnaeus, 1758) and Emys trinacris Fritz et al, 2005
We provide a sound population genetic database covering the whole distribution of E. trinacris in Sicily for management and conservation actions for this threatened pond turtle
Allnumber studied of microsatellite loci were highly polymorphic, with alleleinnumbers ranging from 7and to 30,GENELAND

Summary

Introduction

The western Palaearctic genus Emys Duméril, 1805 contains two species, Emys orbicularis (Linnaeus, 1758) and Emys trinacris Fritz et al, 2005. Galloitalica (corresponding to mitochondrial lineage V) occur in peninsular Italy and Sardinia [5,6,7]. Emys trinacris, characterized by the mitochondrial lineage III, is endemic to Sicily (Italy) and is the only autochthonous pond turtle occurring there [2,9,10]. The taxonomic status of the Sicilian pond turtle is currently debated. When it was described, species status was inferred by nuclear-genomic fingerprinting [2] and later confirmed using nuclear microsatellite markers [5,7]. Speybroeck et al [11] proposed treating the taxon as a subspecies of E. orbicularis, reflecting the weak genetic divergence of E. trinacris and E. orbicularis compared to other European reptiles. To avoid unnecessary nomenclatural changes, we here continue to treat E. trinacris as a distinct species until new genetic evidence becomes available

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Conclusion