Mitochondrial genome assembly and comparative mitogenomics of five snake
mackerels (Perciformes, Gempylidae).
Abstract
The Gempylidae (snake mackerels) family, belonging to the order
Perciformes, consists of about 24 species described in 16 genera
primarily distributed in tropical, subtropical, and temperate areas
worldwide. Despite substantial research on this family utilizing
morphological and molecular approaches, taxonomy categorization in this
group has remained puzzling for decades prompting the need for further
investigation into the underlying evolutionary history among the
gempylids using molecular tools. In this study, we characterized and
compared eight complete mitochondrial genomes for five Gempylidae
species [Neoepinnula minetomai, Neoepinnula orientalis, Rexea
antefurcata, Rexea prometheoides, and Thyrsites atun] using
Ion-Torrent sequencing. Using Bayesian Inference and Maximum-Likelihood
tree search methods, we investigated the evolutionary relationships of
seventeen Gempylidae species using mitogenome data. In addition, we
estimate divergence times for extant gempylids. We identified two major
clades that formed approximately 48.05 (35.89 – 52.04 mya) million
years ago; Gempylidae 1 [Lepidocybium flavobrunneum, Ruvettus
pretiosus, Neoepinnula minetomai, Neoepinnula orientalis, and Epinnula
magistralis], and Gempylidae 2 [Thyrsites atun, Promethichthys
prometheus, Nealotus tripes, Diplospinus multistriatus, Paradiplospinus
antarcticus, Rexea antefurcata, Rexea nakamurai, Rexea prometheoides,
Rexea solandri, Thyrsitoides marleyi, Gempylus serpens, and Nesiarchus
nasutus]. The present study demonstrates the superior performance of
complete mitogenome data compared to individual genes in phylogenetic
reconstruction. In addition to Cytochrome c oxidase subunit 1, NADH
dehydrogenase subunit 2, and Cytochrome b, which are frequently employed
in phylogenetic investigations, NADH dehydrogenase subunit 5 provided
adequate resolving power. Analyses of selection pressure revealed
purifying selection is predominant in Gempylidae mitogenomes. By
including T. atun individuals from different regions we demonstrate the
potential for the application of mitogenomes in species phylogeography.