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

Posted by
  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...

From past to a precarious future: climate change threatens protected Mexican tarantulas

Posted by

 


From past to a precarious future: climate change threatens protected Mexican tarantulas

Abstract

Climate change has an impact on the distribution of numerous species around the world, which for many signifies an increase in the risk of extinction. Human activities, especially the pet trade, often have a negative impact on tarantula spiders. Many species of Mexican tarantulas are considered endangered, such as those that belong to the Tliltocatl complex. Using two datasets containing individuals determined anatomically and/or genetically to be Tliltocatl vagans (Ausserer 1875), we developed distribution models using the MaxEnt algorithm considering past, present, and future climate scenarios. Past scenarios range from the last interglacial period through to the middle Holocene period and future scenarios consider the RCP 4.5 and the RCP 8.5. Our current distribution model of T. vagans covers the known distribution of the genus Tliltocatl. During the last interglaciation (LIG) period, the modelled distribution of this genus was extensive in Central and South America, before being markedly restricted during the last glaciation event. The current distribution is also more concentrated in southern Mexico compared to the initial distribution during the LIG. Future modelled distributions based on the increased temperature scenarios show a drastic decrease in suitable areas, with potential extinction risks in the western part of their current distribution. Given the current context of increasing human activity in the southern regions of Mexico and the future effects of climate change, there is great cause for concern for the conservation of Mexican tarantulas, particularly if no measures are taken to ensure their survival.

Hénaut, Y., Machkour-M’Rabet, S., Shillington, C. et al. From past to a precarious future: climate change threatens protected Mexican tarantulas. J Insect Conserv 29, 54 (2025). https://doi.org/10.1007/s10841-025-00686-4