A Deep Divergence in the Cold: Yagania, a New Genus of Ghost Spider from Isla de Los Estados, Argentina (Araneae: Anyphaenidae)

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  A Deep Divergence in the Cold: Yagania, a New Genus of Ghost Spider from Isla de Los Estados, Argentina (Araneae: Anyphaenidae) Abstract (1) Background: Ghost spiders of the family Anyphaenidae are well represented in Tierra del Fuego, although the evergreen forests of this region are notably understudied. (2) Methods: We based our work on a previous phylogenetic analysis of four markers, studied the morphology using microscopy, and characterized the habitat by vegetation and climate. (3) Results: An undescribed species from Isla de los Estados represents a deeply diverging lineage, which we describe here as Yagania chuanisin n. gen. and n. sp. (4) Conclusions: This species is likely associated with cold and rainy evergreen forests found only in specific areas of Tierra del Fuego Archipelago, where further sampling should be focused to better evaluate the species’ geographic range, as well as its conservation status. Ramírez, M. J., Magalhaes, I. L., Lencinas, M. V., & Martí...

Convergent evolutionary adaption of spider venom from predation to defense

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Convergent evolutionary adaption of spider venom from predation to defense

Abstract

Most spiders deploy paralytic venom for prey capture, but adults of the yellow sac spider (Cheiracanthium punctorium) instead produce a predominantly defensive venom to safeguard their offspring. Here, we characterized 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 showed that CSTXs arose following the mygalomorph-araneomorph split ca. 300 mya by means of ancestral gene duplication and functional specialization. A gene fusion event then merged CSTXs from two distinct clades to form the double domain toxin. PLA2 proteins were 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 natures tendency to use the same molecular solutions for similar ecological challenges across diverse animal lineages.

Convergent evolutionary adaption of spider venom from predation to defense. Tim Lueddecke, Sabine Hurka, Josephine Dresler, Thomas Luebcke, Volker von Wirth, Guenter Lochnit, Thomas Timm, Volker Herzig, Andreas Vilcinskas. bioRxiv 2025.03.05.641688;