Complete mitochondrial genomes of two sand diver species (Perciformes, Trichonotidae): novel gene orders and phylogenetic position within Gobiiformes

The complete mitochondrial genome sequences of two species of the family Trichonotidae, Trichonotus elegans (Shimada and Yoshino 1984) and Trichonotus filamentosus (Steindachner 1867), were determined using a polymerase chain reaction-based method. The genomes ranged from 16,517 to 17,235 bp in length and included 37 genes (13 protein-coding genes, 22 transfer RNA genes, and 2 ribosomal RNA genes) and two non-coding regions (control region and origin of the light strand replication) as in other vertebrates. However, they shared a unique gene order among vertebrates with multiple gene switching and insertions. Phylogenetic analysis showed that Trichonotidae and Apogonidae are sister groups, which together with Kurtidae are placed as a closely related clade of Gobioidei. These results would be useful for analyzing the evolutionary relationships of Gobiiformes and the evolutionary study of fish mitogenomes.