Characterization of the mitochondrial genome of Rhipicephalus linnaei Audouin, 1826 (Arachnida: Ixodida: Ixodidae) and phylogenetic considerations of the Rhipicephalus sanguineus complex

The Rhipicephalus sanguineus s.l. complex encompasses a group of ixodid tick species distributed on a global scale. These are obligatory hematophagous ectoparasites of vertebrates, which hold significant relevance for public and veterinary health, as they serve as vectors for various pathogens. Furthermore, the phylogenetic relationships within this complex have long been a subject of discussion. Therefore, in this study, we report the complete characterization of two mitochondrial genomes of the species Rhipicephalus linnaei from different places in the state of Pará, Amazon, Brazil. Using high-throughput sequencing, sequences of 14,710 bp and 14,709 bp were obtained (R. linnaei PZ055104 and R. linnaei PZ055103, respectively), comprising 37 functional subunits and two A+T-rich regions (CR1 and CR2), corresponding to the control regions. Phylogenetic analysis using Maximum Likelihood, based on the 13 protein-coding regions, grouped the obtained sequences within the clade formed by representatives of the Rhipicephalus sanguineus complex. Additionally, the R. linnaei sequences clustered into a strongly supported clade (bootstrap > 98%), together with other sequences of the same species from different parts of the world. These sequences provide essential information for phylogenetic, evolutionary, and taxonomic studies of the group. Moreover, they contribute to the correct species delimitation and to the understanding of relationships between geographically distinct populations. Considering the importance of the genus Rhipicephalus as a pathogen vector, these genomes expand the scientific support for control strategies. Thus, the mitochondrial genomes of R. linnaei constitute a valuable resource for science and public health.