Species Identification of coral reef fishes by DNA barcode from Chuuk Micronesia

Abstract

The fish diversity of Chuuk Micronesia is currently under threat due to rapid changes in the coral reef ecosystem. Accurate fish identification using DNA barcode is fundamental for exploring species diversity and resource protection. In this study, we analyzed the mitochondrial DNA cytochrome c oxidase I (COI) barcodes of 162 fish samples obtained from Chuuk Micronesia. We identified 95 species from 53 genera in 26 families and 7 orders. The average Kimura 2-parameter genetic distances within species, genera, families, and orders were calculated as 0.17%, 11.78%, 15.63%, and 21.90%, respectively. Average nucleotide composition of the 162 DNA barcodes was T = 29.08%, C = 28.39%, A = 24.18%, and G = 18.35%. The average GC and AT contents were 46.74% and 53.26%, respectively.

Acanthuridae, Scaridae, Serranidae, and Labridae were dominant among the 26 families that appeared through COI DNA barcode information from coral reef fish collected in this study. Also, we have utilized DNA barcode sequences to perform genetic divergence and phylogenetic analysis of the four families recognized as dominant groups in Chuuk State. Analysis showed that Scaridae was the most recently diverged and well adapted group. On the other hand, Labridae was found to be a group that diverged early and settled long ago.

In addition, the results of this study confirmed that COI DNA barcode is an effective approach to the identification of coral reef fishes with various morphological characteristics. We anticipate that the results of this study will provide baseline data for the protection of coral reef fish biodiversity at Chuuk Micronesia.