Hidden diversity in plain sight: four new species of Nemesia (Araneae: Mygalomorphae) from the Córdoba Province of Spain

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  Hidden diversity in plain sight: four new species of Nemesia (Araneae: Mygalomorphae) from the Córdoba Province of Spain Abstract A taxonomic revision of the species of Nemesia Audouin, 1826, distributed in the vicinity of Córdoba City, southern Spain, is presented. Four new species are described: Nemesia morana sp. nov. (female), N. kodama sp. nov. (male and female), N. rosae sp. nov. (male and female), and N. tamajoni sp. nov. (male and female). These species are distinguished by distinct morphological characters, including the shape of the spermathecae, palpal bulbs, and spinnerets, as well as by burrow architecture. Fieldwork was conducted across two of the three major habitat types in the region—the humid, forested mountains of Sierra Morena and the croplands and riparian forests of the Guadalquivir Valley—while the third, the “campiña”, which is mainly composed of agricultural landscapes, remains poorly explored. Sampling methods included pitfall trapping and the direct e...

Identification of a novel insecticidal chlorotoxin-like peptide from the venom of the Compsobuthus egyptiensis scorpion

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Identification of a novel insecticidal chlorotoxin-like peptide from the venom of the Compsobuthus egyptiensis scorpion

Abstract

Scorpion venom contains various bioactive peptides, but there are many scorpion species whose venom has not been studied. The genus Compsobuthus, belonging to the family Buthidae, is relatively diverse, but there have been no reports on their venom components. In the present study, we characterized venom components of the Compsobuthus egyptiensis scorpion inhabiting the northern Egyptian desert. Mass spectrometry analysis of the venom revealed that the components with molecular masses from 3000 to 4000 Da were relatively abundant among 198 components detected. We then isolated a novel insecticidal peptide, Ce-1, from one of the HPLC fractions showing insecticidal activity. The structure of Ce-1 was determined using a combination of Edman degradation and de novo MS/MS sequencing analyses. This revealed that Ce-1 consists of 36 amino acid residues with four disulfide bonds. The deduced structure was confirmed by comparison with the synthetic peptide. Ce-1 shares high sequence homology to chlorotoxin-like peptides, which consist of an α-helix and an antiparallel triple-stranded β-sheet cross-linked by four disulfide bonds. Future research on Ce-1 will contribute to elucidating the mechanism of action of insecticidal chlorotoxin-like peptides.
Megaly, A. M. A., Nakamichi, R., Wakayu, M., Nakagawa, Y., Abdel-Wahab, M., & Miyashita, M. (2025). Identification of a novel insecticidal chlorotoxin-like peptide from the venom of the Compsobuthus egyptiensis scorpion. Toxicon, 108556. https://doi.org/10.1016/j.toxicon.2025.108556