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

  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...

Uaica gen. nov., a new genus of huntsman spiders from the Brazilian Amazonia (Araneae: Sparassidae)

 


Uaica gen. nov., a new genus of huntsman spiders from the Brazilian Amazonia (Araneae: Sparassidae)

Abstract

The new genus Uaica gen. nov. is proposed to include five new species, the type species, Uaica uatuma gen. et sp. nov. (♂♀) and U. mapia gen. et sp. nov. (♂) from Amazonas, U. carapiranga gen. et sp. nov. (♂♀), from Pará, U. karipuna gen. et sp. nov. (♂) from Rondônia and U. juruena gen. et sp. nov. (♀), from Mato Grosso, all from the Brazilian Amazonia. The new genus seems to be closely related to Caayguara Rheims, 2010, Meri Rheims & Jäger, 2022, Nungara Pinto & Rheims, 2016, and Sadala Simon, 1880. All species are described and illustrated, and a distribution map is provided.

Rheims, C. A. (2025). Uaica gen. nov., a new genus of huntsman spiders from the Brazilian Amazonia (Araneae: Sparassidae). European Journal of Taxonomy989(1), 24–49. https://doi.org/10.5852/ejt.2025.989.2879