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...

Can size make a difference? Cross-predation occurrences between lizards and scorpions in the Brazilian seasonal dry tropical forest

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Can size make a difference? Cross-predation occurrences between lizards and scorpions in the Brazilian seasonal dry tropical forest

ABSTRACT

Cross-predation is an important event that may influence prey–predator dynamics, especially in arid and semiarid ecosystems. In this study, we report four predation events involving lizards and scorpions from different sites in the Brazilian seasonal dry tropical forest. In three of these events, the lizard acted as the predator, while in one event, the scorpion was the predator. Body size played a determining role when lizards were the predator of the scorpion, with larger vertebrates feeding on the arachnids. In contrast, when the sizes were similar, the scorpion acted as the predator of the lizard. Our findings suggest a complex relationship between lizards and scorpions in the Brazilian seasonal dry tropical forest.

Silva-Júnior A.O.1, Brito-Almeida T.R.1, Feitosa M.L.B.2, Jansen R.G.3, Peres M.4, Azevedo R.5, Moura G.J.B.6, Barbosa A.R.7, Lira A.F.A.8 2023. Can size make a difference? Cross-predation occurrences between lizards and scorpions in the Brazilian seasonal dry tropical forest // Invertebrate Zoology. Vol.20. No.3: 343–347 [in English].