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...

Quantifying Venom in African Snakes: Insights into Protein Content, Yield and Body Size Associations

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Quantifying Venom in African Snakes: Insights into Protein Content, Yield and Body Size Associations

Abstract

Snake venoms are complex mixtures primarily composed of toxic proteins used during prey capture and defence. There is limited knowledge concerning the protein concentration of snake venom and the biases of different protein determination methods. Here, we assess the ability of the Qubit protein assay, bicinchoninic acid (BCA) assay, Bradford assay and NanoDrop spectrometry (A280 with a mass extinction coefficient of one) to accurately quantify protein concentrations of toxins isolated from venom, including three-finger toxins and phospholipase A2. The Bradford assays severely underestimated three-finger toxin concentrations and NanoDrop spectrometry overestimated phospholipase A2 concentrations, whilst the BCA assay was the most accurate. Venom from five major African venomous snake genera was also assessed: coral cobras (Aspidelaps spp.); mambas (Dendroaspis spp.); cobras (Naja spp.); bush vipers (Atheris sp.); adders (Bitis spp.); and saw-scaled vipers (Echis sp.). Protein concentration results were inconsistent between methods. Protein concentrations were found to be lowest for Bitis spp. venom and highest for Naja spp. venom and did not vary between species of the same genus. However, in general, Elapidae species had venoms with significantly higher protein concentrations than Viperidae species. Moreover, there was greater variability between Elapidae species. We also determined wet venom yields and used this to provide a tentative estimate of the total protein quantity that may be injected during a snake bite. We found snake weight and length influenced wet venom yield for the Atheris squamigera but not for Bitis arietans and Echis romani. Our results aim to improve our understanding of the physical properties of snake venom.
French, S., Da Silva, R., Have, M. T., Crittenden, E., Rowley, P., Cullen, I. C., Holland, Z., Wilkinson, M. C., & Modahl, C. M. (2026). Quantifying Venom in African Snakes: Insights into Protein Content, Yield and Body Size Associations. Toxicon: X, 100245. https://doi.org/10.1016/j.toxcx.2026.100245