Fishes of the families Lethrinidae (emperors) and Lutjanidae (snappers) are commercially important in South China Sea. However, in terms of morphology, they can be confused because of a basic “fish-like” shape with large mouths and notched tails. In Vietnam, however, classification system of fish species based primarily on morphological characteristics. Therefore, the number and distribution of many species is still controversial. The purpose of this study was to clarify the phylogeny of commercial fish species of the genus Lethrinus and Lutjanus distributed in Vietnam. Currently 4 lethrinid and 4 lutjanid species are described based on morphologic characters. Combine with Genbank sequences, a phylogenetic tree was constructed based on 16S gene of mitochondrial DNA using Maximum parsimony, maximum likelihood and Bayesian inference approaches.

The phylogram showed that two families exhibit monophyly with differences of species range sequence from 1.9% to 3.9% in Lethrinus and from 1.9% to 4.4% in Lutjanus. Additionally, 16S sequences of current species were identical to sequences of the same species reported in Genbank. Continue sampling of commercial fish species and classification based on morphology and genetics to build DNA barcoding of fish species in Vietnam is really necessary.