Structure and evolution of the complete mitochondrial genome of the freshwater drum, Aplodinotus grunniens (Actinopterygii: Perciformes: Sciaenidae)

Abstract

Background. Overfishing and habitat degradation caused a decline of populations of many fish species belonging to the speciose family Sciaenidae. A reliable taxonomic framework is a prerequisite for implementing effective stock management and conservation measures, but phylogeny and taxonomy of the Sciaenidae remain poorly resolved. As traditionally used morphological and single gene-based molecular markers carry a too limited phylogenetic signal for the task, mitochondrial phylogenomics may be a more suitable tool. The freshwater drum, Aplodinotus grunniens Rafinesque, 1819, is one of the few Sciaenidae species that live in freshwater habitats, which makes it an important model for studying the phylogeny and evolution of Sciaenidae. Materials and methods. We sequenced and characterized its mitogenome, and reconstructed the phylogeny of Sciaenidae using mitogenomes of 28 species. Results. The architecture of the mitogenome (16487 bp in length) is standard for this family, and three typical elements were identified in the control region: extended termination associated sequences, central conserved region, and conserved sequence block. Poor availability of sciaenid mitogenomes (especially those belonging to different lineages) prevented us from resolving the phylogeny of this family with confidence. Notably, our results indicate that Larimichthys and Collichthys species may belong to a single genus, and we suspect that the mitogenome of Chrysochir aureus (Richardson, 1846) has been misidentified taxonomically, and urge its resequencing. Conclusion. The sequencing of additional mitogenomes belonging to non-represented and poorly represented lineages is needed to facilitate the understanding of phylogeny and taxonomy of Sciaenidae.