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...

A blast from the past: Acanthoctenus alux Arizala, Labarque & Polotow, 2021, an exotic spider in The Netherlands, imported many decades ago (Araneae: Ctenidae)

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A blast from the past: Acanthoctenus alux Arizala, Labarque & Polotow, 2021, an exotic spider in The Netherlands, imported many decades ago (Araneae: Ctenidae)

Abstract 

Exotic species can be introduced accidentally through human activity to regions where they do not occur naturally. Fruit and produce shipments offer a means by which trapped specimens can accidentally travel long distances bringing, for example, tropical species deep into temperate regions. Documenting, identifying, and tracking these introductions can help evaluate the potential threats these species could pose for local biodiversity and, in rare cases, human health. We report a new exotic species in the Netherlands from a specimen captured more than 60 years ago from a fruit shipment. The species, Acanthoctenus alux (Arizala, Labarque & Polotow, 2021), was described recently in a revision of the genus Acanthoctenus, and is only known from female specimens. Here, we provide documentation of the specimen including the external genitalia, and somatic characters like eyes, spinnerets, calamistrum, and the cribellum.

Rivera-Quiroz, F. A., Helsdingen, P. J. van & Miller, J. A. (2025). A blast from the past: Acanthoctenus alux Arizala, Labarque & Polotow, 2021, an exotic spider in The Netherlands, imported many decades ago (Araneae: Ctenidae). Arachnology 20(2): 313-315.