Phylogeography of Bark Scorpions (Centruroides exilicauda) from the Baja California peninsula
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Authors
Acosta, Athenea
Issue Date
2025-09-12
Item Type
Thesis
Language
en_US
Keyword
Alternative Title
Abstract
Scorpions are an arthropod order known for their potent venom and stinger. We currently recognize over 2,800 species, which are mainly differentiated using morphology. Bark Scorpions (Buthidae: Centruroides) occur across the southern and western United States and western and northern Mexico. They have also been recorded in Central America and northern South America. The low vagility of these animals makes them ideal candidates to study biogeographic and phylogeographic patterns, especially in areas with great biogeographical complexity. This thesis investigates the phylogeographic patterns of Centruroides exilicauda, a species distributed across the Baja California peninsula. Phylogenetic analysis of the cytochrome oxidase subunit I (COI) sequences from 24 sequences (21 sequenced here) plus seven outgroup samples revealed the presence of two distinct clades within this species, one restricted to the south (the Cape), and another one distributed across the peninsula. The divergence of these two clades predates the split of the peninsula from mainland Mexico. While the focus on this work is not new, as it builds on previously published studies, it aims to provide further insights into the biogeographic process influencing these patterns. A key framework for understanding these divergences is the mid-peninsular seaway hypothesis, which proposed that a historical water barrier may have influenced the genetic isolation of Centruroides populations along the Baja California peninsula. Further studies are needed to clarify the taxonomic status of these clades and to determine whether the Northern and Southern clades represent distinct species.