Bothrops venom variation drives niche-specific pharmacology through Ca²⁺ signalling and membrane damage

Snake venom activity exhibits evolutionary patterns within genera and varies according to ecological niche. By examining venoms from species inhabiting distinct environments, niche-specific functional differences can be uncovered. Bothrops, a diverse and medically important Neotropical pit viper genus, shows known clade-specific differences in coagulotoxicity. Here, we expanded this framework by assessing intra-clade variation in cellular activity across twelve Bothrops species using a high-content fluorescence assay that simultaneously measures ion channel responses and membrane cytotoxicity. Most venoms induced rapid membrane damage and cell lysis, whereas arboreal species lacked both activities, suggesting reduced selection for these activities. In contrast, the terrestrial Bothrops mattogrossensis and Bothrops pauloensis, which are sister species inhabiting the Pantanal wetlands and outskirts, respectively, displayed unique intracellular calcium-modulatory effects in the absence of membrane disruption. High throughput venomics revealed candidate toxin families underlying these calcium responses. Our findings demonstrate niche-specific diversification of venom bioactivity and highlight Bothrops venoms as promising sources of pharmacological agents.