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...

Thwaitesia margaritifera O. Pickard-Cambridge, 1881: A New State Record of Mirror Cob Web Spider Species (Araneae: Theridiidae) in Chhattisgarh, India

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Thwaitesia margaritifera O. Pickard-Cambridge, 1881: A New State Record of Mirror Cob Web Spider Species (Araneae: Theridiidae) in Chhattisgarh, India

Abstract

This study documents the first recorded occurrence of the mirror cobweb spider Thwaitesia margaritifera O. Pickard-Cambridge, 1881 in Chhattisgarh, India, and the first record of the genus Thwaitesia in the state. Two adult female specimens were collected by hand from the foliage of a Shorea robusta tree in a forested area of Gariaband District on 27 March 2026. Live specimens were photographed, preserved in 70% ethanol, and examined using a stereo zoom microscope. Identification was based on the morphology of the carapace, abdomen, eyes, legs, spinnerets, and female genital structures, followed by comparison with published taxonomic descriptions. The specimens were characterised by a small, pale greenish-yellow cephalothorax with a dark median stripe, a large laterally compressed abdomen bearing irregular reflective scale-like patches, eight eyes arranged in two rows, and a leg formula of I–IV–II–III. The epigynum was rounded, with a V-shaped posterior protrusion, oval spermathecae, and copulatory ducts coiled twice. The specimens were collected from a single locality and represent a distributional record rather than evidence of abundance or wider occurrence. This finding adds T. margaritifera to the documented spider fauna of Chhattisgarh and provides morphological information for future locality-based surveys. Further sampling across seasons, habitats, and districts is required to clarify the species’ distribution within the state. 


Nayak, Jashavant & Nichat, Avinash & Harris, K.K. & Warte, Hitesh. (2026). Thwaitesia margaritifera O. Pickard-Cambridge, 1881: A New State Record of Mirror Cob Web Spider Species (Araneae: Theridiidae) in Chhattisgarh, India. Asian Journal of Research in Zoology. 9. 183-190. 10.9734/ajriz/2026/v9i3299.