A new species of the mygalomorph spider genus Euagrus Ausserer (Araneae: Euagridae) from central Mexico and new records of E. gus Coyle from Tlaxcala

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  A new species of the mygalomorph spider genus Euagrus Ausserer (Araneae: Euagridae) from central Mexico and new records of E. gus Coyle from Tlaxcala Abstract  A new species of the spider genus Euagrus Ausserer, 1875 from temperate pine-oak forests in the states of Tlaxcala and Hidalgo, Mexico is described: E. pulque sp. nov. The description of the new species is based on male and female adult specimens. Additionally, Euagrus gus Coyle, 1988 is recorded for the very first time in the state of Tlaxcala. These species have sympatric distributions in La Malinche National Park, Tlaxcala. With this description, the diversity of the genus increases to 23 species, with Mexico harboring the highest diversity with 17 described species.  Valdez-Mondragón, A., Salinas-Velasco, H. V. & Bueno-Villegas, J. (2026). A new species of the mygalomorph spider genus Euagrus Ausserer (Araneae: Euagridae) from central Mexico and new records of E. gus Coyle from Tlaxcala. Zootaxa 5810 (...

Comparative venomics suggests an evolutionary adaption of spider venom from predation to defense

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Comparative venomics suggests an evolutionary adaption of spider venom from predation to defense

Abstract

Most spiders deploy paralytic venom for prey capture, but adults of the Nurse´s thorn finger (Cheiracanthium punctorium) instead produce a predominantly defensive venom to safeguard their offspring. Here, we characterize the molecular repertoire of C. punctorium venom to shed light on its evolutionary history. Unlike venom in other spiders, C. punctorium venom mostly comprises neurotoxic double-domain neurotoxin 19 family (CSTX) peptides and enzymes, such as phospholipase A2 (PLA2). Comparative venomics in four spiders representing two infraorders shows that CSTXs arise following the mygalomorph–araneomorph split ~300 mya by means of ancestral gene duplication and functional specialization. A gene fusion event then appeared to have merged CSTXs from two distinct clades to form the double-domain toxin. PLA2 proteins are convergently recruited to C. punctorium to fulfil a defensive function and are strikingly similar to proalgesic PLA2 proteins in bee venom. These complex, multimodal molecular innovations in venom systems highlight nature’s tendency to use the same molecular solutions for similar ecological challenges across diverse animal lineages.

Lüddecke, T., Hurka, S., Dresler, J., Lübcke, T., Von Wirth, V., Lochnit, G., Timm, T., Herzig, V., & Vilcinskas, A. (2025). Comparative venomics suggests an evolutionary adaption of spider venom from predation to defense. Communications Biology, 8(1), 1-11. https://doi.org/10.1038/s42003-025-09015-6