Spatial genetic structure in the Eurasian otter (Lutra lutra) meta-population from its core range in Italy

Abstract

We characterized the genetic structure of the Eurasian otter (Lutra lutra) meta-population living in the core of its Italian distribution range providing results from 191 fresh spraints, collected from 24 watercourses included in Southern Italy. Furthermore, according to ecological corridors and barriers, we discuss the likely ways of movement and possible evolutionary fate of these populations. We genotyped 136 samples using 11 Lut microsatellite nuclear markers amplified from faecal dna. Microsatellites were moderately variable (Ho = 0.45; He = 0.46), with a total number of alleles and average number of alleles per locus in the meta-population of 50 and 4.54, respectively. No significant heterozygosity excess was observed in meta-population suggesting no recent population bottlenecks. Bayesian clustering discriminated a sub-structuring of the meta-population in five putative clusters, indicating that local populations are genetically differentiated: three of these seem to be identifiable with geographically defined sub-populations (from the Cilento, Agri and Basento river basins). The fourth is represented by multiple sub-populations with admixed genotype, that include genotypes from the Lao, Sinni and Abatemaco river basins, living in a landscape with the higher environmental permeability. Landscape genetic analysis could provide evidence of an unexpected ecological corridor: the seacoast, highlighted, for the first time as a new way for the dispersion of the South-Italian otters. Deepening the knowledge of these perspectives is crucial to identify solid strategies aimed at the future health of the populations of the Italian otters, by restoring dispersal corridors and managing the watercourses.