Diversity And Structure Of Trout Populations (Salmo Sp., Salmonidae, Actinopteri) In The Zumberak-Samoborsko Gorje Nature Park In Croatia

The diversity of trout (genus Salmo) in Croatia is still not well described on several levels, resulting in a range of taxonomic controversies and conservation issues, especially in protected areas. The aim of this study was to determine genetic diversity and spatial distribution of trout in the Zumberak-Samoborsko Gorje Nature Park in Croatia using mitochondrial cytochrome b sequences, and to estimate the stability of their populations for conservation. Effective population sizes and migration rates, and intraspecific and intrapopulational genetic diversities were also estimated. Phylogenetic reconstruction revealed three evolutionary independent and genetically distinct lineages, comprising 26 haplotypes. The majority of samples and haplotypes belong to S. labrax, the native species for this region. Even though S. labrax is widespread in the watercourses of the park and is present with moderately high genetic diversity, haplotypes of non-native S. India and S. marmoratus were also observed. In addition to the presence of non-native trout species, survival of native trout in this area is also endangered by habitat fragmentation and other anthropogenic pressures, causing conservational concern.