# Comparative Analysis of Mitochondrial Genome from Phormictopus cancerides (Arachnida: Theraphosidae) with Phylogenetic Implications

## TL;DR

This study analyzes the mitochondrial genome of Phormictopus cancerides to better understand the evolutionary relationships among tarantulas.

## Contribution

The first characterization of the mitogenome of Phormictopus cancerides and its phylogenetic implications for Theraphosidae.

## Key findings

- The mitogenome of P. cancerides is 13,776 bp with a high A/T nucleotide preference.
- ND3 gene showed the highest evolutionary rate, while COX1 evolved more slowly.
- Theraphosinae is closely related to Harpactirinae and Selenocosmiinae based on mitogenome analysis.

## Abstract

Tarantulas represent a highly diverse taxonomic group and play a crucial role in ecosystems. To gain a deeper understanding of the evolutionary relationships within the family Theraphosidae, in this study, we characterized the mitochondrial genome (mitogenome) of Phormictopus cancerides for the first time. The mitogenome is a typical circular double-stranded molecule, with a size of 13,776 bp. P. cancerides exhibited an A/T nucleotide preference (61.9–68.5% A + T content), with their rRNAs and tRNAs showing higher values than PCGs and the CR. The genes and the gene order were consistent with other Theraphosidae mitogenomes. The mitogenome was compacted and showed a bias for A/T. Ka/Ks analyses showed that the ND3 gene had the highest evolutionary rate, while the COX1 gene displayed a relatively slower evolution. Our phylogenetic analysis based on mitogenomes showed the subfamily Theraphosinae is closely related to the subfamily Harpactirinae and the subfamily Selenocosmiinae. Our results could contribute to the study of relationships within the family Theraphosidae and lay the foundation for further studies on tarantulas.