Comparative analysis of mitochondrial genomes reveals family-specific architectures and molecular features in scorpions (Arthropoda: Arachnida: Scorpiones).

• We have assembled 8 new scorpion mitogenomes from transcriptomic datasets, annotated and described them in detail. We duplicated the number of scorpion mitogenomes available at NCBI. • We performed a comparative analysis and confirmed the differential synteny of the family Buthidae with respect to other scorpions. • The family Buthidae invariably showed differential patterns in the molecular characteristics of mitogenomes with respect to other scorpions. Scorpions are a group of arachnids with great evolutionary success that comprise more than 2,000 described species. Mitochondrial genomes have been little studied in this clade. We describe and compare different scorpion mitochondrial genomes and analyze their architecture and molecular characteristics. We assembled eight new scorpion mitochondrial genomes from transcriptomic datasets, annotated them, predicted the secondary structures of tRNAs, and compared the nucleotide composition, codon usage, and relative synonymous codon usage of 16 complete scorpion mitochondrial genomes. Lastly, we provided a phylogeny based on all mitochondrial protein coding genes. We characterized the mitogenomes in detail and reported particularities such as dissimilar synteny in the family Buthidae compared to other scorpions, unusual tRNA secondary structures, and unconventional start and stop codons in all scorpions. Our comparative analysis revealed that scorpion mitochondrial genomes exhibit different architectures and features depending on taxonomic identity. We highlight the parvorder Buthida, particularly the family Buthidae, as it invariably exhibited different mitogenome features such as synteny, codon usage, and AT-skew compared to the parvorder Iurida that included the rest of the scorpion families we analyzed in this study. Our results provide a better understanding of the evolution of mitogenome features and phylogenetic relationships in scorpions. [ABSTRACT FROM AUTHOR]