Snake venoms have evolved over millions of years to subdue prey and deter predators rapidly. The potency and amount of venom differ both within and across species, and are primarily influenced by their ecology and environment. Understanding venom yields in clinically relevant species is essential for refining treatment approaches for snakebite. Despite this, venom yields have seldom been documented, especially in snakes of the Indian subcontinent. To address this knowledge gap, we analysed venom yields from 338 specimens of the clinically most important “big four” Indian snakes— Naja naja , Daboia russelii , Bungarus caeruleus , and Echis carinatus —collected across diverse biogeographic and agroclimatic zones. We systematically compared yields across different genders, regions, and life stages to uncover patterns in venom production and explored the relationship between venom yield and dry weight. Our findings reveal substantial inter- and intraspecific variation, with N. naja and D. russelii exhibiting the highest average yields, while B. caeruleus and E. carinatus produced much lower quantities. Geographic variation was significant for B. caeruleus , but not for the other species. No sex-based differences were observed; however, life stage was an important determinant, with adults producing more venom than juveniles or subadults. Comparative analysis with captive populations indicated that captivity may not substantially alter venom yields. By integrating venom yield and toxicity data, we highlight the distinct envenomation strategies among the big four snakes and their implications for snakebites. These insights are crucial for improving antivenom production, clinical management, and understanding the ecological and evolutionary dynamics of Indian snake venoms.

Snakebite envenoming is a major yet neglected tropical disease in sub-Saharan Africa, where antivenom efficacy is critically limited by intraspecific venom variation shaped by local ecological pressures. Nigeria’s sharply contrasting Sudan Savanna (North) and Lowland Rainforest (South) provide an ideal natural system to investigate this variation, yet a comparative analysis of its medically important snakes has been lacking. We conducted an integrated proteomic and functional characterization of venoms from the puff adder (Bitis arietans) and black-necked spitting cobra (Naja nigricollis) collected in Kaduna (North) and Ibadan (South). Using high-resolution LC-MS/MS, SDS-PAGE, and biochemical assays (phospholipase A₂, protease, fibrinogenolytic, hemolytic, and coagulation activities), we mapped region-specific venom compositions and characterized their functional activities. Bitis arietans displayed region-associated divergence: southern venom was enriched in serine proteases, whereas northern venom was dominated by lectins and distinct snake venom metalloproteinase isoforms. Naja nigricollis showed a conserved phospholipase A₂/three-finger toxins backbone, yet southern venoms exhibited elevated snake venom metalloproteinase III and L-amino acid oxidase. These molecular differences manifested functionally, with southern B. arietans venom showing higher protease activity than northern B. arietans, whereas southern and northern N. nigricollis venom exhibited similar protease activity but enhanced phospholipase A₂ activity in southern N. nigricollis. This work provides the first integrated proteomic and functional comparison of venoms from northern and southern Nigerian venom sample of B. arietans and N. nigricollis. While based on a limited number of individuals, the observed differences should be considered preliminary and indicative of potential regional trends rather than population-level characteristics.