Fig. 3

Median-joining haplotype network based on a) 831 sequences of cytb including 15 2nNCRC and 816 specimens of Carassius (see Additional file 3 in Supplementary Information) derived from GenBank, where the specimens of Carassius in the network were found: A the Europe, except for the south of Alpes mountains and Danube River basin, B the south of Alpes mountains and Danube River basin in Europe, C Western Asia, D Siberia in Russia and Mongolia, E China, F Southeast Asia, G the Japan and Ryukyu Islands; and b) 128 sequences of cytb of C. auratus complex just distributed in China. The size of the circles represents haplotype frequency. Each connecting line represents a single nucleotide substitution, and each little short line represents mutated position. The haplotypes of different geographic samples were represented as different colors