Thermal ecology of Plesiopelma longisternale: novel insights and comparative analysis with a sympatric species

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  Thermal ecology of Plesiopelma longisternale: novel insights and comparative analysis with a sympatric species Abstract Understanding thermal responses in ectotherms is key to assessing vulnerability to climate change. Tarantulas (Theraphosidae) are informative models due to their sedentary lifestyle, long life cycles, and reliance on specific microhabitats. We present the first integrative assessment of the thermal ecology of Plesiopelma longisternale , a widespread Argentine species, combining experimentally derived thermal limits and thermal preferences with species distribution models, and compare its thermal profile with the sympatric Grammostola vachoni to explore patterns of thermal niche differentiation. Plesiopelma longisternale showed a minimum thermal limit near 4 °C, a maximum near 44 °C, a thermal optimum of 29.5 °C, a narrow thermal performance breadth, and a preferred temperature of approximately 32 °C. Models integrating climatic and thermal parameters predicted...

Analysis of the Proteome and Biochemistry of Venom from Tityus confluens, a Scorpion That Can Be Involved in Severe Envenomation Cases in Brazil

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Analysis of the Proteome and Biochemistry of Venom from Tityus confluens, a Scorpion That Can Be Involved in Severe Envenomation Cases in Brazil

Abstract

In Brazil, the annual scorpion sting cases surpass those of other neglected tropical diseases, highlighting a significant public health issue. The severity of scorpion envenomation relates to the venom’s rapid action, complex composition, species identification challenges, and limited antivenom availability. This work aimed to characterize the venom of Tityus confluens through proteomic, enzymatic, and biological analyses while also assessing its reactivity to anti-scorpion antivenom. The electrophoretic analysis revealed seven protein bands, with the most prominent bands at 30, 15, and 10 kDa. The C18-RP-HPLC analysis isolated sixteen primary fractions. The proteomic analysis identified various toxins, including potassium channel toxins, sodium channel toxins, and antimicrobial peptides, as well as other proteins such as hypotensin and metalloproteinases. Antigenic components were identified in the T. confluens venom, which displayed dose-dependent but time-independent amylolytic activity. The ATPase activity significantly increased with 1–10 μg of venom. No cytotoxic effects were observed on carcinoma or non-tumoral cell lines. The T. confluens venom features a complex protein composition rich in toxins that target ion channels and enzymes. It exhibits active enzymatic and antigenic properties, and displays low cytotoxicity. This is the first proteomic research on the composition of T. confluens venom and may provide valuable insights into understanding the clinical manifestations of scorpion stings.

Lima LC, Covali-Pontes HR, Leite OGS, Perdomo RT, Moraes LFRNd, Migliolo L, Moyses MN, Santos NGPd, Pimenta DC, Rodrigues MS, et al. Analysis of the Proteome and Biochemistry of Venom from Tityus confluens, a Scorpion That Can Be Involved in Severe Envenomation Cases in Brazil. Toxins. 2025; 17(8):406. https://doi.org/10.3390/toxins17080406