Distinct matrilines in the panmictic population of the European eel

Determining the genetic population structure and intraspecific evolution of species is important for efficient management. Here we investigated 394 sequences of the mtDNA cyt b of the critically endangered European eel, Anguilla anguilla. We found 62 different haplotypes, among which 32 novel ones. All those sequences were grouped into 9 haplogroups on the basis of their frequency and links in the haplotype network. Two pairwise comparisons revealed significant genetic differentiation between regions. One comparison indicated small (ΦST = 0.02768; P = 0.0071) genetic differentiation between the Atlantic Ocean and the North Sea. Another comparison indicated small (ΦST = 0.01144; P = 0.0440) genetic differentiation between eel samples caught in the Baltic Sea, the Curonian Lagoon and the Gulf of Riga and those captured in the North Sea. The results of the study are in agreement with the recent findings obtained using the mtDNA D-loop region as a molecular marker, indicating that although A. anguilla is considered a panmictic species the genetic structure of its population indicated by mtDNA markers could be characterized as a genetic mosaic.