How to ensure a species remains in oblivion: the history of Nemesia hispanica L. Koch, 1871 (Araneae: Mygalomorphae: Nemesiidae)

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  How to ensure a species remains in oblivion: the history of Nemesia hispanica L. Koch, 1871 (Araneae: Mygalomorphae: Nemesiidae) Abstract The taxonomic history of Nemesia hispanica L. Koch 1871 is revised; it is a species long affected by misidentifications since 1871. New material from Monte Abantos, San Lorenzo de El Escorial, Madrid (Spain) is analyzed, providing the first descriptions of males, adult females, and burrow structure—particularly relevant given that the holotype seems to be an immature specimen. Morphology of copulatory organs and the distinctive burrow architecture allow clear differentiation from other morphologically related species. Finally, the historical chain of misidentifications is examined, along with its implications for Iberian nemesiid diversity and taxonomy. Pertegal, C., Narro, A. & Olivares, P. (2026) How to ensure a species remains in oblivion: the history of Nemesia hispanica L. Koch, 1871 (Araneae: Mygalomorphae: Nemesiidae). Zootaxa , 5869...

Functional diversity and behavioural use of fibre-producing silk glands in Pholcus phalangioides

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Functional diversity and behavioural use of fibre-producing silk glands in Pholcus phalangioides

Spiders possess multiple types of silk glands producing silks with contrasting properties. The behavioural use of the different glands is poorly known, limiting our understanding of the function–property correlation in spider silks. Here, we investigated the involvement of three fibre-producing silk glands (major ampullate, minor ampullate and aciniform glands) in locomotory, predatory, web construction and reproductive behaviours by the cosmopolitan cellar spider, Pholcus phalangioides (Pholcidae). To generate a comprehensive understanding of the function of different silks, a multidisciplinary approach was deployed, encompassing microscopy, cryo-fixation during behaviours, high-speed video recordings and mechanical measurements (tensile testing) of different silk products. The results challenge the one-gland-one-function paradigm, revealing that multiple silk types are often employed in combination and gland activation patterns are variable. Notably, of all investigated silk products, only the aerial dispersal lines uniquely relied on only one type of silk, underscoring its specialisation. Tensile testing uncovered significant variation in mechanical properties between different silk products, with walking draglines exhibiting the highest load and stress–strain values. Toughness values of the mixed silk bundles were comparable to those of the high-performing major ampullate silks of araneid spiders, demonstrating that independent pathways may lead to the evolution of high-performance biological materials. These findings emphasise the versatility of silk uses in spiders, offering new perspectives on the interplay between diversified silk properties and behavioural ecology in spiders.

Maitry Jani, Siripanyo Promnil, Paula Heinz, Daniele Liprandi, Jonas O. Wolff; Functional diversity and behavioural use of fibre-producing silk glands in Pholcus phalangioides. J Exp Biol 1 November 2025; 228 (21): jeb250392. doi: https://doi.org/10.1242/jeb.250392