Conservation genetics of mediterranean barbel specie inside natura 2000 sites: an ecosystem perspective

Abstract

Freshwater fishes of the Italian peninsula are, at present, potentially highly threatened by climate change, human activities, increasing demands for water, natural resources fragmentation and loss of habitat. Genus Barbus are threatened in Italy by hybridization and introgression caused by allochthonous lineages. This thesis presents a novel dataset including both mitochondrial (255 samples) and nuclear DNA markers (191 samples) in Barbel species inside 15 Natura 2000 sites. Moreover, ecological indices (ISECI, IFF, STAR_iCM) and environmental data (BOD5, TSS , NH4+, NO3-,NO2-, pH, T) were also analysed inside 15 Protected Areas of Natura 2000 sites. Scientific objectives were the following: detecting the evidence of significant population structure in Barbus plebejus and Barbus caninus and determining introgression and hybridization between native species and other barbel species. Moreover, the last objective was to explain phylogenetic relationships among populations in different hydrogeographic districts and to define whether ecological factors were correlated with genetic factors. Results showed complex scenarios where different species live in the same habitat allowing hybridization and introgression. In addition to these, an altitude gradient between native and allochthonous species was observed. Physical, chemical and ecological data reinforces the existence of an altitudinal zonation in term of barbel species representativeness among sites. These evidences mirrored anthropogenic disturbance, climate change and loss of habitat inside considered Protected Areas. All results will be managed inside European LIFE program NAT/IT/001129 BARBIE for future restocking and spawning activities.