Molecular investigation and morphological characterization for identification of autochthonous brown trout populations from Abruzzo rivers (central Italy)

This research wants to broaden the knowledge about the size and distribution of brook trout in the Abruzzo region. Moreover we want to provide a tool for future management actions. Was chosen an integrated approach: the characterization of the specimens (n = 208) was made with phenotypic analysis and the use of two molecular markers, then evaluating the level of introgression brought by non-native strains. From the study of mtDNA were identified the individuals related to the evolutionary lines Atlantic, Adriatic and, in twoe sites, even Marble; instead was not found specimens with Mediterranean haplotypes sensu Bernatchez (2001). The contextual investigation with nuclear DNA study has identified the presence of hybrids. Results of molecular analysis are in some cases inconsistent with the livery features. In general, the results show a high impairment of the naturalness of the trout populazions of Abruzzo, both in qualitative and quantitative terms: this specie is absent in 34% of investigated sites and, where it was present, their populations are composed of alien individuals alien ( 25%) or hybrid (75%). From a first analysis, this alteration was due to the massive restocking with Atlantic individuals during the last years for fishery. Integrating biological and environmental data will be possible confirm or refute this hypothesis. In the basins of Sangro and Aterno-Pescara were identified residual populations with a low introgression rate and therefore worthy of study.