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...

New records and invasion risk of Stenochrus portoricensis Chamberlin, 1922 (Schizomida: Hubbardiidae) in Brazil

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New records and invasion risk of Stenochrus portoricensis Chamberlin, 1922 (Schizomida: Hubbardiidae) in Brazil

Abstract

Stenochrus portoricensis Chamberlin, 1922 is a schizomid native to the Caribbean and Central America and is notable for facultative parthenogenesis and a broad synanthropic distribution. It is widely reported as an exotic species in several regions worldwide, with recognized invasive potential. Here, we expand its known distribution in Brazil by documenting the first records from the state of Mato Grosso and new occurrences in tourist caves in Bahia. We also model the species’ potential distribution in South America using the Maximum Entropy (MaxEnt) algorithm under current and future climate scenarios. The models indicate higher habitat suitability in regions characterized by low annual temperature variation and consistent rainfall patterns, conditions typical of tropical and subterranean environments, and predict range expansion under future climate change, particularly under the SSP5-8.5 scenario. The reproductive strategy of facultative parthenogenesis, combined with broad ecological tolerance, association with human-disturbed environments, and increasing spatial proximity to native schizomids, reinforces the invasive potential of S. portoricensis. These findings highlight the urgent need to investigate its ecological interactions and impacts on native communities, especially subterranean fauna, which exhibit high endemism and sensitivity to disturbance.


Duarte, M. V. da S. A., Jansen, R. G., Oliveira-Neto, M. A. de, Seabra, V. L., & Gallão, J. E. (2026). New records and invasion risk of Stenochrus portoricensis Chamberlin, 1922 (Schizomida: Hubbardiidae) in Brazil. Papéis Avulsos De Zoologia, 66, e202666040. https://doi.org/10.11606/1807-0205/2026.66.040