South-east Europe, along with the adjacent region of south-west Asia, is an important biodiversity hotspot with high local endemism largely contributed by contemporary continental lineages that retreated to southern refugia during colder Quaternary periods. We investigated the genetic diversity of the European bitterling fish (Rhodeus amarus) species complex (Cyprinidae) across its range in the western Palearctic, but with a particular emphasis in the region of Balkan, Pontic and Caspian refugia. We genotyped 12 polymorphic microsatellite loci and a partial sequence of mitochondrial gene cytochrome b (CYTB) for a set of 1,038 individuals from 60 populations. We used mtDNA sequences to infer phylogenetic relationships and historical demography, and microsatellite markers to describe fine-scale genetic variability and structure. Our mtDNA analysis revealed six well-supported lineages, with limited local co-occurrence. Two lineages are distributed throughout central and western Europe (lineages "A" and "B"), with two zones of secondary contact. Another two lineages were restricted to the Ponto-Aegean region of Greece (lineages "C" and "D") and the final two lineages were restricted south of the Caucasus mountains (lineage "E" from the Black Sea watershed and lineage "F" from the Caspian watershed). A signal of recent expansion was revealed in the two widespread lineages and the Ponto-Aegean lineage "C". The geographic distribution of clusters detected by nuclear microsatellites corresponded well with mitochondrial lineages and demonstrated finely sub-structured populations. A profound population structure suggested a significant role of genetic drift in differentiation among lineages. Lineage divergence in the Ponto-Aegean and Caspian regions are substantial, supporting the validity of two described endemic species (Rhodeus meridionalis as lineage "D" and Rhodeus colchicus as lineage "E") and invite taxonomic evaluation of the other two southern lineages (Thracean "C" and Caspian "F").

Department of Basic Sciences Faculty of Fisheries Recep Tayyip Erdogan University 53100 Rize Turkey

National Museum Department of Zoology Václavské nám 68 115 79 Prague 1 Czech Republic

National Museum of Natural History Bulgarian Academy of Sciences 1 Tsar Osvoboditel Blv 1000 Sofia Bulgaria

The Czech Academy of Sciences Institute of Animal Physiology and Genetics Laboratory of Fish Genetics Rumburská 89 277 21 Liběchov Czech Republic; Department of Biology and Ecology Faculty of Science University of Ostrava Chittussiho 10 Ostrava 710 00 Czech Republic

The Czech Academy of Sciences Institute of Vertebrate Biology Květná 8 603 65 Brno Czech Republic

The Czech Academy of Sciences Institute of Vertebrate Biology Květná 8 603 65 Brno Czech Republic; Department of Botany and Zoology Faculty of Science Masaryk University Kotlářská 2 611 37 Brno Czech Republic

The Czech Academy of Sciences Institute of Vertebrate Biology Květná 8 603 65 Brno Czech Republic; Department of Ecology and Vertebrate Zoology University of Łódź Banacha 12 16 90 237 Łódź Poland; School of Biology and Bell Pettigrew Museum of Natural History University of St Andrews St Andrews KY16 8LB UK

Citace poskytuje Crossref.org