Two new arthropod toxins purified from the venom of the Mexican scorpion Centruroides nigrescens

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  Two new arthropod toxins purified from the venom of the Mexican scorpion Centruroides nigrescens Abstract The venom of the slender black scorpion Centruroides nigrescens , from the State of Guerrero México, was fractionated by Sephadex G–50 gel filtration, followed by carboxymethyl cellulose ion separation and high–performance liquid chromatography, permitting to obtain two new peptides toxic to arthropods. The estimate LD 50 of the soluble venom for the insect Acheta domesticus was 11.1 μg/g body weight, and for the arthropod Armadillidium vulgare was 61.1 μg body weight . The amino acid sequence of toxin Cnige1 (toxic to A. domesticus and A. vulgare ) contains 65 amino acids, with a molecular mass of 7273.37 mass units, whereas toxin Cnige2, toxic to A. domesticus , contains 68 amino acids, with a molecular mass of 7548.81 units. Both peptides are well packed, containing 8 cysteines, which in the native venoms are forming 4 disulfide bridges each. The amino acid sequences f...

The pholcid spiders of Tunisia (Araneae: Pholcidae): new species, new records, and deep COI divergence in Holocnemus reini

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The pholcid spiders of Tunisia (Araneae: Pholcidae): new species, new records, and deep COI divergence in Holocnemus reini

Abstract

Tunisia features a rapid transition between Mediterranean and Saharan biogeographical zones, resulting in a high degree of environmental heterogeneity. Despite this ecological diversity, Tunisian spiders have received limited attention compared to those of neighboring Maghreb countries. Here we combine the results of recent collections in Tunisia focusing on Pholcidae with a comprehensive review of previously published information, resulting in a total of six genera and eleven species. We present first records of the genera Micropholcus Deeleman-Reinhold & Prinsen, 1987 and Spermophorides Wunderlich, 1992 for Tunisia, represented by four new species: M. kahinae Huber sp. nov., M. echebbii Huber sp. nov., S. nabilae Huber & Kmira sp. nov., S. bchirae Huber sp. nov.; in addition, we redescribe S. huberti (Senglet, 1973) from Tunisian specimens, describe the previously unknown female of Pholcus genuiformis Wunderlich, 1995, provide new records for species previously documented for Tunisia, and provide a key to the Pholcidae genera of Tunisia. We analyze previously published and newly generated CO1 barcodes of Tunisian pholcids and of putatively closely related taxa and document deep genetic divergence between Moroccan and Tunisian specimens of Holocnemus reini (C. Koch, 1873) (up to 17%). We discuss the apparent correlation between arid environments and higher than usual intraspecific genetic distances. Such environments are often characterized by fragmentation, habitat isolation, and harsh conditions, and these factors may promote rapid genetic divergence, especially in poor dispersers.

Huber, B.A., Meng, G. & Kmira, G. (2026) The pholcid spiders of Tunisia (Araneae: Pholcidae): new species, new records, and deep COI divergence in Holocnemus reini. Zootaxa, 5881 (1), 1–46. https://doi.org/10.11646/zootaxa.5881.1.1