Abstract：To investigate the molecular phylogenetic relationships of Scarus, partial sequences of COⅠ genes from 16 parrotfish were obtain by PCR amplification and sequencing. Combining with two COⅠ sequences of Chlorurus species from NCBI, genetic distances among different parrotfish were computed using MEGA7.0 software, and the phylogenetic trees were constructed basing on Neighbor joining and Maximum likelihood method. Results showed that: 18 parrotfish mainly formed three clades, genus Cetoscarus formed a separate clade, which was located at the base of the phylogenetic tree; Genus Scarus had a high evolutionary status and was located at the top of the tree, while genus Chlorurus was between the two Cetoscarus and Scarus. Chlorurus gibbus and Chlorurus sordidus were not grouped within the genus Scarus, but were clustered inside the genus Chlorurus, which supported the taxonomic view that they were classified into Chlorurus. The phylogenetic relationship between Scarus schlegeli and Scarus psittacus was close, but the COⅠ genetic distance between them was 0.085, higher than the species identification critical value (0.020), indicating that they were two independent species. The COⅠ genetic distance between Scarus rivulatus and Scarus globiceps was 0.017, which was less than the critical value (0.020). But there were great differences in morphology, excluding the possibility of homonymy, it might be natural hybridization or gene penetration between them.
2021, Vol. 34 
