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...

Modelling the potential distribution and conservation scenarios for the troglobitic spider Pinelema elinae Brescovit, Gallão & Cizauskas, 2023 (Telemidae) in the Neotropics: palaeoclimatic evidence and current threats

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Modelling the potential distribution and conservation scenarios for the troglobitic spider Pinelema elinae Brescovit, Gallão & Cizauskas, 2023 (Telemidae) in the Neotropics: palaeoclimatic evidence and current threats

Abstract

Pinelema elinae Brescovit, Gallão & Cizauskas, 2023 (Telemidae) is the first formally described troglobitic spider of the family Telemidae in Brazil, known from seven caves in Bahia, northeastern Brazil. As a strictly subterranean species with a highly restricted range, it faces significant conservation threats in the Serra do Ramalho karst, an unprotected area under intense anthropogenic pressure. We modelled the potential distribution of P. elinae and the genus Pinelema across the Neotropics using the MaxEnt, based on current climate, Mid-Holocene (∼8.3–4.2 kya), Last Glacial Maximum (∼21 kya) data, and future projections under the SSP5-8.5 scenario (2061–2080). During the Last Glacial Maximum, suitable habitat was fragmented into four refugia, with caves probably acting as climatic microrefugia. In current conditions, highly suitable areas (>50%) cover ∼1.87 x 107 km2, but only 17.6% overlap with conservation units. Future projections indicate a redistribution of suitability towards the central-west, southeast, and northeast of Brazil, with a net gain concentrated outside protected areas. Land-use analysis in the Serra do Ramalho (2008–2023) revealed a 138% increase in agriculture and a 4% loss of native vegetation. These results highlight the need for conservation strategies targeting karst landscapes, especially establishing a conservation unit in Serra do Ramalho.

Duarte, M. V., Gallão, J. E., & Bichuette, M. E. (2026). Modelling the potential distribution and conservation scenarios for the troglobitic spider Pinelema elinae Brescovit, Gallão & Cizauskas, 2023 (Telemidae) in the Neotropics: Palaeoclimatic evidence and current threats. Biological Journal of the Linnean Society, 149(1). https://doi.org/10.1093/biolinnean/blag063