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...

Passive transponder implantation in Theraphosidae: A tool for traceability and conservation

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Passive transponder implantation in Theraphosidae: A tool for traceability and conservation

Abstract

  1. Illegal wildlife trade represents a major global threat to biodiversity, with tarantulas among the most heavily trafficked invertebrate groups due to increasing demand in the international pet market, highlighting the urgent need for effective regulatory frameworks and reliable specimen-level traceability systems to distinguish legally bred individuals from illegally sourced ones.
  2. Individual identification is essential to support legal trade, strengthen enforcement mechanisms and reduce illegal trafficking; therefore, this study evaluated the feasibility and safety of passive integrated transponder microchip (PIT TAG) implantation for individual identification in multiple tarantula species under controlled laboratory conditions.
  3. Post-implantation parameters assessed included anaesthesia recovery time, feeding behaviour, ecdysis frequency, PIT TAG retention across successive moults and reproductive performance, integrating physiological, behavioural and life-history endpoints to provide a multidimensional evaluation of short- and long-term effects. All individuals tolerated the implantation procedure without mortality or severe adverse effects; recovery times were short, with normal feeding behaviour resuming within expected time frames, ecdysis occurred normally, with PIT TAGs remaining stable and detectable after successive moults, and reproductive parameters—including mating success and ootheca production—were not negatively affected, with no evidence of interference in behaviour, development or reproduction.
  4. This study provides the first comprehensive dataset assessing behavioural and reproductive outcomes following PIT TAG implantation in tarantulas and demonstrates that the technique is a safe and effective method for individual identification and long-term traceability, with potential to support regulatory enforcement, promote legal trade and contribute to conservation efforts by reducing illegal wildlife trafficking.
Lago, M., Bellini Lucas, M. S., Bremer, H., Pinto, I. B., Cupello, M., Ferreira, V. R., Carneiro, A. K., & Maciel, L. Passive transponder implantation in Theraphosidae: A tool for traceability and conservation. Insect Conservation and Diversity. https://doi.org/10.1111/icad.70075