Genetic structure and differentiation of four lake populations of Coilia ectenes (Clupeiformes: Engraulidae) based on mtDNA control region sequences

To investigate genetic structure and differentiation of four lake populations of Coilia ectenes, a total of eighty-one individuals from four largest freshwater lakes (Dongting DT], Poyang PY], Chaohu CH], Taihu TH]) were analyzed based on mtDNA control region sequences. Seventy-five haplotypes were detected, and four to seven 38 bp tandem repeats were found. The indexes of nucleotide diversity (π) in these four populations were DT 0.78%, PY 1.09%, CH 0.81%, and TH 0.62%. Genetic distances within populations were between 0.63 and 1.14%, and from 0.76 to 1.60% among populations. A Neighbor–Joining (NJ) tree consisted of three major clades. Clade 1 consisted of 88.89, 26.09, and 4.55% individuals of DT, PY, and CH. Analysis of molecular variance (AMOVA) showed that most variances occurred within populations, suggesting that this is the main source of total variance. Our results suggest that the four lake populations of C. ectenes have not developed significant genetic structure.