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...

Abdominal pattern polymorphism and distribution of the giant golden orb-weaving spider, Nephila pilipes (Fabricius, 1793) (Araneae: Araneidae), in the Philippines

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Abdominal pattern polymorphism and distribution of the giant golden orb-weaving spider, Nephila pilipes (Fabricius, 1793) (Araneae: Araneidae), in the Philippines

Abstract 
The giant golden orb-weaving spider, Nephila pilipes (Fabricius, 1793), is notable for its color polymorphism. Here, we report the pattern polymorphism of this species. A Nephila species with unusual abdominal patterning from the Philippines is confirmed herein as N. pilipes based on its somatic structures and genitalia. The abdominal pattern consists of rows of subquadrate yellow spots on the dorsum, which is distinct from the typical longitudinal yellow stripes in N. pilipes. We provided the distribution of the spotted variant based on citizen science data on the internet, suggesting that this particular variation may be regionally endemic in the Philippines. Keywords: aposematism, arachnids, citizen science, intraspecific variation, Nephilinae. 


Acuña, Darrell & Maglangit, Erl Pfian & Santiago, Myla & Guevarra Jr, Leonardo. (2025). Abdominal pattern polymorphism and distribution of the giant golden orb-weaving spider, Nephila pilipes (Fabricius, 1793) (Araneae: Araneidae), in the Philippines. Philippine Journal of Systematic Biology. 18. AZ-BB. 10.26757/pjsb202418006.