Frontiers in Marine Science (Nov 2015)
Babylonian confusion of gudgeons in the west Aegean drainages inferred by the mitochondrial DNA analyses
Abstract
Gudgeons (Gobio and Romanogobio, Cypriniformes) are taxonomically very complicated group of primary freshwater fishes. The region of the west Aegean Sea rivers is inhabited by three species according to Kottelat and Freyhof (2007): Gobio feraensis endemic to the Pinios River basin; Gobio balcanicus inhabiting all remaining drainages, from the Aliakmon up to the Marica drainage; and Romanogobio elimeus occurring from the Pinios to the Vardar basin. Recent analysis of barcoding gene cytochrome c oxydase suggested presence of additional two well differentiated lineages in the Aegean rivers (Geiger et al. 2014): Romanogobio banarescui from the Vardar River and Gobio bulgaricus (based on material from Asian part of Turkey only). We have analysed control region (mitochondrial non coding DNA) of gudgeon populations from all larger river drainages from the west Aegean region (Pinios to Marica basins). Included were also several populations from surrounding areas of the Danube River drainage and from the Black Sea rivers. The results are not at all congruent with the proposed taxonomy. MtDNA haplotypes of Romonagobio banarescui were found not only in the Vardar, but also in the lower Aliakmon River. Haplotypes of Romanogibo elimeus were found in the Pinios, upper Aliakmon and Loudias rivers. Situation of genus Gobio is completely confusing; there is no geographic structure in the distribution of haplotypes. Many different haplogroups are shared in some basins, especially in the drainages of the Struma, Mesta and Marica rivers. This indicates complicated evolutionary history of gudgeons in the region, probably having several historical refugia, and with multiple recent contacts of lineages. Our data indicate a contact between the Danubian, Black Sea and Aegean rivers. The taxonomic status of most of the populations of Gobio from the west Aegean area remains unclear.
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