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...

SPIDER RESEARCH ON ST HELENA: PAST, PRESENT AND FUTURE

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SPIDER RESEARCH ON ST HELENA: PAST, PRESENT AND FUTURE

Abstract


Spiders (Araneae Clerck 1757) constitute the largest and most diverse lineage of arachnids, totaling over 51,000 currently valid described species (World Spider Catalog 2023), although the total number of known species is likely to be upwards of double of this figure (Platnick and Raven 2012). The presence of spinnerets (a type of silk producing organ) is a unique morphological feature found in no other animal (Murphy and Roberts 2015).Their presence in areas of human habitation and the intriguing behaviour of some families has made spiders ubiquitous in human culture and societies (Nentwig et al. 2022). St Helena is one of the world’s most remote islands and its fauna and flora is of worldwide importance (Ashmole and Ashmole, 2000); with more than fifty endemic plants, the famous Wirebird, and hundreds upon hundreds of endemic invertebrates. Spider research on St Helena has been conducted intermittently by only a handful of workers in the last 150 years, starting in the 1860s and continuing to the present day. In this article, we chronicle the history of spider research on the island, focusing on both the spiders and the researchers behind their discovery and investigation.

Sherwood, Danniella & Fowler, Liza. (2023). Spider research on St Helena: past, present and future. 52. 2-22.