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...

First insights into the role of evolutionary history in shaping venom composition of Vipera ammodytes

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First insights into the role of evolutionary history in shaping venom composition of Vipera ammodytes

Abstract

Understanding intraspecific venom variation requires distinguishing the contributions of neutral population history from natural selection. This study aims to determine whether venom variation in the Vipera ammodytes species complex is structured across eight phylogenetic lineages. Despite a complex evolutionary history, venom composition did not differ among phylogenetic units within the analytical framework used, suggesting that shared ancestry alone does not explain venom variation. Whether local adaptation to environmental conditions explains the observed variation remains an open question for future studies.
Lakušić, M., Piccoli, C., Anđelković, M., Andonov, K., Burić, I., Brito, J. C., Dyugmedzhiev, A., Merdan, S., Schmid, L., Tzoras, E., Florian-Hempel, B., & Martínez-Freiría, F. (2026). First insights into the role of evolutionary history in shaping venom composition of Vipera ammodytes. Toxicon, 109256. https://doi.org/10.1016/j.toxicon.2026.109256