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

  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...

Three new and exceptional Damarchus species from Thailand (Araneae: Bemmeridae)

 


Three new and exceptional Damarchus species from Thailand (Araneae: Bemmeridae)

Abstract

Damarchus pylorus sp. nov., D. lanna sp. nov. and D. dao sp. nov. are described from males and females collected in western and northern Thailand. Damarchus pylorus sp. nov. and D. lanna sp. nov. are morphologically unique within the genus by males having a para-embolic apophysis and a keel composed of coarse laminae on the lower (posterior) side of the palpal organ, and by females having sperm receptacles, composed of a strongly sclerotized base and an unsclerotized head, situated on the ventral side of a relatively long genital atrium. The distantly related D. dao sp. nov. is distinguished from all other congeners by males having a tibia I coupling spur with three megaspines. Presumed relationships of these three species and of the genus Damarchus are discussed. Information on biology and burrow structures of the new species is provided. Damarchus pylorus sp. nov. stands out by plugging the side shaft of its burrow with a soil pellet; similar plugging devices in unbranched burrows are known from other spider families.

https://www.mapress.com/zt/article/view/zootaxa.5336.4.2

Schwendinger, P. J. & Hongpadharakiree, K. (2023). Three new and exceptional Damarchus species from Thailand (Araneae: Bemmeridae). Zootaxa 5336(4): 481-508. doi:10.11646/zootaxa.5336.4.2

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