New mitochondrial genomes of three whip spider species from the Amazon (Arachnida, Amblypygi) with phylogenetic relationships and comparative analysis

The complete mitochondrial genomes of the whip spiders Charinus carajas, C. ferreus, and Heterophrynus longicornis were sequenced, annotated, and compared with other mitogenomes of whip spiders and arachnids. The three new mitogenomes have the 37 genes usually observed in Metazoa: 13 protein-coding genes (PCGs), 22 transfer RNAs (tRNAs), and two ribosomal RNAs (rRNAs), plus a non-coding control region (CR). Most PCGs presented an ATN start codon, except cox1 in both Charinus species, initiating with TTA. Most PCGs terminated with stop codons TAA or TAG, except nad5 of C. carajas and cox3 of H. longicornis, which presented an incomplete stop codon (T). The Ka/Ks ratios were less than one for all the PCGs, indicating these genes are under purifying selection. All the tRNAs, except for serine 1 (trnS1), had the typical cloverleaf-shaped secondary structure. All the phylogenetic analyses resolved Charinus carajas and C. ferreus as monophyletic groups. Nonetheless, we did not recover the monophyly of Heterophrynus longicornis. The phylogenies under partitioned models did not recover suprageneric taxonomic groups as clades, but the Bayesian inference under the CAT infinite mixture model recovered the family Phrynidae and the superfamily Phrynoidea as monophyletic groups.