When Tarantula Venom Comes from a Misnamed Spider: The Importance of Taxonomic Accuracy in Theraphosid Toxinology

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  When Tarantula Venom Comes from a Misnamed Spider: The Importance of Taxonomic Accuracy in Theraphosid Toxinology I am very happy to share my most recent publication in Toxicon. This is a particularly meaningful publication for me because it brings together two areas that have become an important part of my work and personal interests: tarantulas and toxinology. At first glance, taxonomy and venom research may seem like two very different fields. In reality, they are closely connected. Before we can properly study the venom of a spider, we need to know which spider we are actually studying. Why the Name Matters A scientific name is much more than a label attached to an animal. It connects that animal to everything we report about it, including its biology, distribution, behavior, venom, toxins, and even its potential medical importance. When a tarantula is incorrectly identified, or when an outdated name continues to be used without considering changes in taxonomy, the problem ca...

Complete Mitochondrial Genome Sequencing of Brachypelma albiceps and Comparative Codon Usage Bias Analysis Across Seven Mygalomorphae Species

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Complete Mitochondrial Genome Sequencing of Brachypelma albiceps and Comparative Codon Usage Bias Analysis Across Seven Mygalomorphae Species

Abstract

Tarantulas (family Theraphosidae) are ecologically significant invertebrate predators in terrestrial ecosystems, but many species face threats from habitat fragmentation and unsustainable collection for the international pet trade. Brachypelma albiceps, a CITES Appendix II-listed species, lacks comprehensive mitochondrial genome characterization, limiting phylogenetic and evolutionary studies. Here, we report a complete mitochondrial genome sequence for B. albiceps (13,856 bp; GC content 32.84%) and provide detailed annotation. The genome exhibits typical metazoan mitochondrial organization, containing 13 protein-coding genes (PCGs), 22 tRNAs, and 2 rRNAs, with an AT-rich nucleotide composition (67.16%) characteristic of arthropod mitochondria. Comparative analyses of B. albiceps and six other Mygalomorphae species revealed strong biases toward A/T-ending codons and avoidance of G/C-ending codons. ENC–GC3s, neutrality, and PR2 analyses consistently indicate that natural selection plays a dominant role in shaping synonymous codon usage, with mutation pressure also contributing. Phylogenetic reconstruction based on 10 high-quality mitochondrial protein-coding genes from 23 spider species confirmed the placement of B. albiceps within the family Theraphosidae and its close phylogenetic relationship to Cyriopagopus species. These results provide valuable genomic resources for the Theraphosidae systematics, enhance our understanding of codon bias evolution, and provide critical DNA barcode data for forensic identification of CITES-regulated specimens in the illegal wildlife trade.

Zhan, Q., Tang, Y., Zhao, Y., Hou, S., Huang, Y., Zhao, X., Chen, Y., & Xue, X. (2026). Complete Mitochondrial Genome Sequencing of Brachypelma albiceps and Comparative Codon Usage Bias Analysis Across Seven Mygalomorphae Species. Biology. https://doi.org/10.3390/biology15010016