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...

Geometric morphometric analysis in nine species of genus Hottentotta (Birula 1908) (Arachnida: Scorpiones) from Iran

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Geometric morphometric analysis in nine species of genus Hottentotta (Birula 1908) (Arachnida: Scorpiones) from Iran

Abstract

Hottentotta Birula, 1908 is one of the most widely distributed buthid scorpions, with more than 40 described species from Africa, across the Middle East, to India. Currently, this genus is represented by ten morphological species in Iran (H. akbarii, H. jayakari, H. juliae, H. khoozestanus, H. lorestanus, H. navidpouri, H. saulcyi, H. schach, H. sistanensis and H. zagrosensis), all of which are endemic or subendemic in Iran. The members of this genus have not been properly studied from the taxonomic point of view. A tool that could contribute to scorpions' taxonomic studies is geometric morphometry, which is defined as the fusion between geometry and biology. In this study, the size and shape variations in sternocoxal structure in Hottentotta populations have been examined using the geometric morphometric method. The goal was to analyze the isometric size and conformation in nine species of Hottentotta. 100 individuals of Hottentotta, collected from different parts of Iran during 2018-2020, were photographed. Coordinate (x, y) configurations from landmarks were registered in sternocoxal structures. Geometric morphometric analyses were performed using R language. The results clearly showed divergence in the shape and size of sternocoxal structure among the studied taxa. However, the major shape changes were associated with H. akbarii which has a larger size of sternocoxal structure and a narrower sternum, shorter coxa II-III, and longer coxa IV.

ResearchGate Link (PDF)

Iranian Journal of Animal Biosystematics (IJAB), Vol.19, No.1, 1-12, 2023, DOI: 10.22067/ijab.2023.81166.1051