The morphological characteristics of the Polynemid fish species distributed in the China Sea are very similar

which can easily lead to classification confusion In this study

we applied DNA barcode technology to analyze the genetic differences between

Eleutheronema tetradactylum

and its related species

Eleutheronema rhadinum

. Mitochondrial COI sequences were obtained from four samples of each species. Among the 655 bp sequences

87 sites were variable. The nucleotide diversity was 0.132 82

and the sequence homology was 93.34%. Moreover，the genetic distance based on the kimura 2parameter model is 0.151

larger than minimum species distance of 0.02. Neighbor-joining phylogenetic analysis revealed that

E. tetradactylum

and

E. rhadinum

are two different but closely related species from the same genus. Using ten random primers

we obtained some specific fragments

and then converted one of them (about 1 300 bp in length

amplified by primer S4) to SCAR marker. Two SCAR markers

SCAR1 (469 bp fragment

62 ℃ annealing temperature) and SCAR5 (606 bp

56 ℃)

were obtained successfully for the species identification of

E. tetradactylum

and its related species. This study would provide technical support for the genetic background research and germplasm conservation of the Polynemid fish species.