Complete mitochondrial genome characterisation of Ratha longimana (H. Milne Edwards, 1834) from the western Atlantic Ocean, with a phylogeny of the Xanthidae (Decapoda: Brachyura)

Abstract The longhand rubble crab Ratha longimana inhabits coral reefs and rocky shores in the subtropical and tropical western Atlantic Ocean. This species was long considered to be the only chlorodielline species present in the area, but has since been transferred to the genus RathaLasley, Lai & Thoma, 2013 and is now thought to belong to an undescribed subfamily within Xanthidae MacLeay, 1838. Here we provide a complete mitochondrial assemblage and characterisation of this species. The assembled mitochondrial genome (hereafter mitogenome) of R. longimana is 15,819 bp in length and contains 13 protein coding genes (PCGs), 22 transfer RNA (tRNA) genes, and two ribosomal RNA (rRNA) genes. The 22 tRNA genes range from 62 to 69 bp in length. A mitochondrial gene order (MGO) analysis revealed a transposition of the tRNA genes Val (V) and 12S rRNA (rrnS) when compared to the ancestral brachyuran gene order, which is in line with earlier studies on xanthoid mitogenomes. Mitogenome data for xanthid crabs (as well as the superfamily Xanthoidea MacLeay, 1838) are currently scarce considering the species richness of the family, limiting the options for phylogenomic studies. This is partially remedied here by providing a new genomic resource for R. longimana.