Joining the dark side: waterfall spiders in subterranean habitats, with the description of a new genus and two new species from Brazil (Araneae: Trechaleidae)

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  Joining the dark side: waterfall spiders in subterranean habitats, with the description of a new genus and two new species from Brazil (Araneae: Trechaleidae) Abstract Trechaleidae is a family of spiders often recognized by its semiaquatic species, but its diversity extends beyond these well-known examples. In this study, we describe Troglotrechalea gen. nov. , a new genus with two novel species, T. faleroae spec. nov. and T. agorai spec. nov. , found exclusively in subterranean habitats within karst formations in central and southeastern Brazil. Both species exhibit pale coloration, but unmodified eyes and legs if compared to other species in the family. The slight degree of troglomorphism, along with their geographic and habitat records, suggests that these species are restricted to hypogean habitats, although they probably move through epigean habitats. Additionally, we report in detail the occurrence of the trechaleid genera Enna O. Pickard-Cambridge, 1897, Heidrunea Brescovi...

Molecular diversity assessed by MALDI mass spectrometry of two scorpion species venom from two different locations in Morocco

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Molecular diversity assessed by MALDI mass spectrometry of two scorpion species venom from two different locations in Morocco

Abstract

Scorpion venom is a cocktail of molecules whose composition is remarkably plastic, controlled by several factors. The Moroccan scorpion fauna is characterized by its richness and high rate of endemism and the venom molecular variability of many species is not yet well characterized. The aim of the present study was to highlight the molecular variability of the venom composition of Androctonus amoreuxi and Buthacus stockmanni (endemic species), both belonging to the Buthidae family, collected from two Moroccan regions, Zagora and Tan-tan. Characterization of the molecular mass fingerprints (MFPs) of each specimen was performed by Matrix-assisted laser desorption ionization-mass spectrometry (MALDI-MS) using a sandwich (Sand) and a dried-droplet (DD) sample preparation and dilutions. Considering these two methods, a total of 828 ion signals were detected, and Sand method produced more adducts (56%) than DD (44%). We observed interspecific variations in the venom composition between these two species showing they share 235 ion signals, while 226 and 367 are specific for these two species, respectively. Moreover, B. stockmanni specimens showed a clear difference in their MFPs between the two geographical areas studied, suggesting intraspecific variations. Moreover, specimens from each population also show an intraspecific variability. In addition, for the same individual, a variation in the venom composition was also recorded depending on the milking frequency. Our results confirmed the presence of characteristic components in each extracted venom sample. In conclusion, MFPs assessed by MALDI-MS represent a fast, non-supervised, sensitive, reliable and cost-efficient approach for taxonomic identification and molecular variability characterization. This study undoubtedly represents a step forward for understanding the scorpion venom plasticity, intra/inter variations, and their temporal and geographical variability.

Ajdi, B., El Asbahani, A., El Hidan, M. A., Bocquet, M., Falconnet, L., Hamza, M. A., Elmourid, A., Touloun, O., Boubaker, H., & Bulet, P. (2023). Molecular diversity assessed by MALDI mass spectrometry of two scorpion species venom from two different locations in Morocco. Toxicon, 107562. https://doi.org/10.1016/j.toxicon.2023.107562