Beyond Venom and Constriction: Bite Performance and Trophic Ecology in the Genus Drymarchon

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  Beyond Venom and Constriction: Bite Performance and Trophic Ecology in the Genus Drymarchon Abstract Snakes exhibit extreme cranial kinesis that facilitates ingestion of prey with large cross-sectional area, but this ability is widely predicted to reduce bite performance due to decreased structural rigidity. Consequently, most large-bodied snakes rely on envenomation or constriction to subdue prey prior to ingestion. Species within the genus Drymarchon represent a notable exception: these large, non-venomous, non-constricting snakes routinely consume a wide range of prey, including large and potentially dangerous vertebrates, using only simple seizing and pinioning behaviors. Here, we quantify bite performance in three species of Drymarchon ( D. corais, D. couperi, and D. melanurus ), examine morphological predictors of biting performance, compare biting pressure to constriction pressure in similarly sized snakes, and synthesize dietary records across the genus. Our results sh...

Antivenom efficacy and Traditional Practices for Snakebite in Brazil: Where Do They Meet?

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Antivenom efficacy and Traditional Practices for Snakebite in Brazil: Where Do They Meet?

Abstract

Snakebite envenoming (SBE) remains a significant public health issue in Brazil, where venom diversity, barriers to timely healthcare, and widespread ethnomedical practices intersect. Venom variability across medically relevant snake species poses important challenges for antivenom design and antigenic coverage in the country. In this context, an integrative review was conducted to examine how venom diversity, antivenom efficacy and protective coverage, and traditional first aid and pre-hospital practices influence the management of snakebite envenoming. Preclinical studies revealed substantial inter- and intraspecific variation in the venoms of Bothrops, Crotalus, Lachesis, and Micrurus species, resulting in heterogeneous venom profiles and biological activities, including lethality that may affect antigenic recognition and neutralization. Although Brazilian antivenoms generally neutralize major toxic activities and reverse life-threatening systemic manifestations of envenoming, there are important limitations in their protective capacity against well-established severe complications such as local tissue damage and neurological syndromes. These limitations are highlighted by the incomplete representation of regional venom diversity in immunization pools and differential toxin immunorecognition. Delayed access to antivenom further worsens clinical outcomes, particularly in remote areas. Concurrently, medicinal plants and first aid and pre-hospital practices were widely used despite limited scientific validation and, in some cases, potential iatrogenic risks to human health. Overall, the available evidence indicates that effective snakebite management in Brazil requires addressing the combined challenges posed by venom variability and current antivenom programs, optimizing antivenom design and coverage, expanding equitable access to healthcare, promoting evidence-based community education, and encouraging the scientific evaluation of safe complementary practices.
Da Silva, W. R. G., Lira, D., Da Cunha Brito, I. M., Justino Vidal, I. S., Lima Bezerra, J. J., Alves, R. R. N., Soares, A. M., Jorge, R. J. B., & Sakamoto, T. (2026). Antivenom efficacy and Traditional Practices for Snakebite in Brazil: Where Do They Meet? Toxicon, 109268. https://doi.org/10.1016/j.toxicon.2026.109268