The first complete mitochondrial genomes for Serranus papilionaceus and Serranus scriba, and their phylogenetic position within Serranidae.

BACKGROUND: Butterfly-winged comber, Serranus papilionaceus Valenciennes, 1832, was recently resurrected and so it is no longer considered as a junior synonym of the Painted comber, Serranus scriba (Linneus, 1758). This calls for a more comprehensive phylogenetic assessment using mitochondria DNA genomes to better understand the relationship and delineate these two species. METHODS AND RESULTS: Next-generation Sequencing was applied to sequence the genome of these two Serranus species. The data generated was then used to construct the mitochondrial genome of these two species. This produced the first complete mitochondrial genomes for the genus Serranus here represented by Serranus papilionaceus and Serranus scriba. These two mitochondrial genomes are 16,514 bp and 16,512 bp respectively, and both contained the typical 37 genes found in vertebrates (13 protein-coding genes, two ribosomal RNAs, 22 transfer RNAs), together with the OL and the control region. CONCLUSIONS: These mitochondrial genomes provide a new insight into the phylogenetic and evolutionary connections between the various subfamilies within Serranidae, while providing new molecular data that can be applied to discriminate between the studied species.

Resurrection of the Butterfly-winged Comber, Serranus papilionaceus Valenciennes, 1832 (Teleostei, Serranidae) and its phylogenetic position within genus Serranus.

The family Serranidae is represented by 92 genera and 579 valid species, with the genus Serranus Cuvier, 1816, containing 30 species. In this study, specimens of Butterfly-winged Comber, Serranus papilionaceus Valenciennes, 1832, were collected from the Canary Islands and compared morphologically and genetically to Painted Comber, Serranus scriba (Linnaeus, 1758), from the Mediterranean Sea. Morphological differences, especially in the colour banding pattern, were corroborated by genetic differences in mitochondrial (COI and ND2) and nuclear (Rhod and PTR) markers. The mitochondrial DNA markers revealed a high level of divergence and no shared haplotypes between the two species (interspecific divergence: COI 4.31%; ND2 8.68%), and a phylogenetic analysis showed that these two species are closely related sister species sharing common ancestry. This study is therefore offering to resurrect S. papilionaceus Valenciennes, 1832 as a valid species increasing the number of eastern Atlantic Serranus species to 11. This should direct new species-specific research, including its population conservation status assessment across its distribution.