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...

Abundance and use of microhabitats by the sicario spider Sicarius thomisoides Walckenaer, 1847 (Araneae: Sicariidae) in various environments of Mejillones, Antofagasta Region, Chile

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Abundance and use of microhabitats by the sicario spider Sicarius thomisoides Walckenaer, 1847 (Araneae: Sicariidae) in various environments of Mejillones, Antofagasta Region, Chile

Abstract

For the spider Sicarius thomisoides Walckenaer, 1847, this study provides data on the frequency and abundance of the species in various vegetation-free environments (ADV), both natural and human-altered, with a predominance of three microhabitats (rocks, trash, and caves), in the area near Mejillones, Antofagasta Region, Chile. The frequency of spider records was very high and similar across the three habitats (between 92% and 100), but the abundance varied significantly depending on the environment, with much significantly higher abundance in the Rock habitat compared to the other two habitats. Regarding microhabitat use, 77.3% of the spiders were found in caves, 41.1% in trash, and 34.7% on rocks. A detailed description of the caves is provided, including the length and height of the entrances, as well as the length and depth of these. The use and quantification of the frequency of trash and caves provide new insights into microhabitat use by this species, as previous studies indicated only the use of rocks. 

Mella Ávila, J. E. ., & Allendes, J. L. . (2026). Abundancia y uso de microhábitats de la araña sicario <em>Sicarius thomisoides</em> Walckenaer, 1847 (Araneae: Sicariidae) en distintos ambientes de Mejillones, Región de Antofagasta, Chile. Revista Chilena De Entomología, 52(3). Retrieved from https://www.biotaxa.org/rce/article/view/88911