The Complete Mitogenomes of Two Species of Snakehead Fish (Perciformes: Channidae): Genome Characterization and Phylogenetic Analysis

Abstract

Channidae (snakehead fish) is a family of medium-to-large freshwater carnivorous fish and contain the genus, Channa. Here, the complete mitogenomes of two Channa fish were determined and comparatively analyzed with the mitogenomes of 16 other Channidae fish species. The two newly sequenced complete mitogenomes were circular DNA molecules with sizes of 16,953 bp (Channa burmanica; OP954106) and 16,897 bp (Channa aurantimaculata; OQ134162). The mitogenomes were composed of 37 genes and one D-loop region. Positive AT skews and negative GC skews were found in the mitogenomes. Most protein-coding genes (PCGs) started with the conventional start codon, ATG; however, the sequence of the stop codon was variable. There was no obvious difference in relative synonymous codon usage among the two mitogenomes, and the two species shared a similar number of codon usage of mitogenomic PCGs, which was also similar to the mean values for the other 15 species of Channa. All Ka/Ks values were <1; cox1 had the lowest value, and atp8 had the highest. All of the tRNAs were typical clover structures, except trnS1. Phylogenetic analysis showed that C. burmanica and C. aurantimaculata shared a close relationship and that they were also closely related to C. gachua. These findings enrich the gene database of Channidae species, clarify the mitochondrial genome structure of the two species, and provide basic data for invasive biological surveillance in the future.