20.500.12556/RUL-184878 Natural colonization and localized admixture across the Adriatic–Danube divide insights from Telestes souffia and Telestes muticellus Along the Adriatic–Danube divide, Pleistocene climatic oscillations intermittently permitted faunal exchange across closely spaced headwaters. We investigated two non-commercial cyprinids, Telestes souffia and T. muticellus, across the Soča drainage (Slovenia–Italy) and adjacent Sava reaches using mitochondrial (cytochrome b) and nuclear (microsatellite) markers. We reveal clear genetic differentiation between T. souffia populations from the Sava and Soča drainages and show that its occurrence within the Soča drainage is restricted to the middle Soča. Genetic patterns indicate that its presence there reflects natural postglacial colonization from the upper Sava rather than recent anthropogenic translocations, highlighting the historical permeability of the Soča–Sava drainage boundary. We further confirm T. muticellus in previously unverified parts of Slovenia, including the Nadiža and Brda watercourses, providing evidence for its native status and supporting refinement of Natura 2000 site designations. A genetically distinct T. muticellus individual from the Vipava river system suggests a historically broader distribution in the lower Soča. Microsatellite data reveal localized introgressive hybridization between T. souffia and T. muticellus in the Volarja Stream, a middle Soča tributary, consistent with recent human-mediated translocations. No evidence for a broad or persistent hybrid zone was detected within the sampled sections of the Soča drainage. cytochrome b introgression microsatellites postglacial colonization Soča river translocation ribe ciprinidi Telestes souffia Telestes muticellus genetska diferenciacija Sava Soča translokacija true false true Angleški jezik Slovenski jezik Članek v reviji 2026-07-16 11:29:33 2026-07-16 11:29:40 2026-07-17 04:30:52 0000-00-00 00:00:00 2026 0 0 Str. 4021–4038 Vol. 853 2026 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 597.2/.5 1573-5117 10.1007/s10750-026-06209-9 274943235 RAZ_Snoj_Ales_2026.pdf RAZ_Snoj_Ales_2026.pdf 1 27697D12B27818C68DCF0C832825B73A 65165508314dda03f462e3f9c9b70d63a5c45d12f724447680c1db0b33e15b51 c29f6a6b-80f8-11f1-9b0d-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=240264 https://link.springer.com/article/10.1007/s10750-026-06209-9 1 b1249ae0-80f8-11f1-9b0d-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=240263 Biotehniška fakulteta 0 0 0