The mitochondrial genomes of Crispatotrochus rubescens and Crispatotrochus rugosus (Hexacorallia; Scleractinia): new insights on the phylogeny of the family Caryophylliidae.

AbstractBackgroundCaryophylliidae is one of the most diverse scleractinian families, however it was recovered as polyphyletic in multiple molecular studies. Recently, the mitochondrial gene order was proposed as a character for a taxonomic revision of the family. Here we describe the first mitogenome of the caryophylliid genusCrispatotrochus, whose phylogenetic position remains uncertain.Methods and resultsThe complete mitochondrial genomes ofCrispatotrochus rubescensandCrispatotrochus rugosuswere sequenced, assembled, and annotated. The two mitogenomes are identical and circular, have a length of 16,536 bp, a GC content of 35.9%, and contain 13 protein-coding genes, 2 ribosomal RNAs and 2 transfer RNAs. Both species have a transposition of a three-genes block –cob,nad2, andnad6– similarly to a group of caryophylliid genera that were recovered as monophyletic and include the type species (Caryophyllia) of the family. The phylogenetic analyses recoveredCrispatotrochuswithin the clade that presents the gene rearrangement and specifically as sister taxa of the genusCaryophyllia, a result consistent with previous studies and the similar gross morphology of the two genera.ConclusionsWe determined the mitochondrial genomes of the genusCrispatotrochusto investigate their relations within Scleractinia. Results from this study provide insights on the phylogenetic position of the genus and corroborate that the mitochondrial gene order could be used as taxonomic character for the family Caryophylliidae.