Comparative mitogenomes of Lobotiformes provides insights into the phylogentic position of Hapalogenyidae

The genus Hapalogenys was one of the most controversial and problematic issue about its phylogenetic position in Perciformes. In this study, the complete mitogenomes of three Hapalogenys species and other five closely related species belong to the same order Lobotiformes were compared. The general sequence characteristics are identical to that of most teleosts, including sequence length, nucleotide content, codon usage frequency and gene arrangement; while the newly sequenced Hapalogenys analis in this study lacks a canonical tRNA-Pro. Two major non-coding regions, the light strand replication origin (OL) and control region (CR) were compared in detail. All OL region were able to form typical stem-loop structures, despite H. analis was obviously shorter in the OL region. Although CR has the fastest evolutionary rate among mitogenome, several conserved structures were found, including the termination associated sequence (TAS), the central conserved blocks (CSB-E, D, and A) and the conserved sequence blocks (CSB-1 and 2) except in H. analis. Both ML tree and BI tree revealed that Hapalogenys genus clustered into a clade and formed a sister group to Datnioididae, supporting the non-Haemulidae relationship of the Hapalogenys group and suggesting its ‘traditional’ place within the Haemulidae is incorrect. These results will not only clarify the mitogenome features of Lobotiformes, but also lay a foundation for further understanding the phylogenetic relationships of Perciformes.