Hunting ecology predicts eye arrangements in the modular visual system of spiders

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  Hunting ecology predicts eye arrangements in the modular visual system of spiders Summary Vision is one of the most important senses used by animals and contributes to fundamental behaviors, including foraging, navigation, and mate detection and selection. 1 Although much is known about how eye position and orientation correlate to ecology in the context of binocularity, 2 animals with multipartite visual systems (more than two eyes) remain comparatively neglected. Spiders are highly successful predators that occupy a range of ecological niches and usually possess eight eyes. Here, we use three-dimensional geometric morphometrics and evolutionary modeling to test whether eye positions, orientations, and interocular angles correlate with hunting strategies in 52 species across the spider phylogeny. We demonstrate that eye configurations diversified from an ancestral medial cluster, as seen in modern trapdoor spiders, to a halo-like configuration in orb-weavers, and to the fronta...

COI-based species delimitation reveals the taxonomic status of two recently described Latrodectus species from Colombia (Araneae: Theridiidae)

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COI-based species delimitation reveals the taxonomic status of two recently described Latrodectus species from Colombia (Araneae: Theridiidae)

Abstract

The comb-footed spider genus Latrodectus Walckenaer, 1805 comprises some of the most medically important spider species due to the potent neurotoxic action of their venom. Despite this relevance, few studies have examined the distribution and presence of Latrodectus in Colombia. Recently, two new species were described from this country based on COI molecular data: Latrodectus hurtadoi Rueda & Realpe, 2021 and Latrodectus garbae Rueda & Realpe, 2021. However, these species lack consistent diagnostic morphological characters and exhibit genetic divergences of ~2%, a level commonly surpassed by intraspecific variation reported in other araneomorph spiders, raising doubts about their taxonomic validity. To assess their status, we reconstructed the phylogeny of Latrodectus using 329 COI sequences representing multiple species obtained from GenBank, including those used in the original descriptions. We applied tree-based (PTP and mPTP) and genetic-distance-based (ASAP) species delimitation methods. Our analyses suggest that L. hurtadoi is likely a valid species within the broader L. hesperus Chamberlin & Ivie, 1935 lineage, a widespread North American taxon that may itself represent a species complex. In contrast, L. garbae is genetically indistinguishable from the Argentine species L. corallinus Abalos, 1980. Therefore, we consider Latrodectus garbae a junior synonym of L. corallinus. These findings highlight the need for integrative taxonomic approaches to Colombian Latrodectus species, which will ultimately improve species identification and the clinical management of envenomation cases.

Zabala-Cruz, M.C. & Hazzi, N.A. (2026) COI-based species delimitation reveals the taxonomic status of two recently described Latrodectus species from Colombia (Araneae: Theridiidae). Zootaxa, 5845 (3), 456–477. https://doi.org/10.11646/zootaxa.5845.3.2