Assessment of the potential toxicological hazard of the Green Parrot Snake (Leptophis ahaetulla marginatus): Characterization of its venom and venom-delivery system.

Snakes are the major group of venomous vertebrates, and the rear-fanged snakes represent the vast majority of species and occur worldwide; however, relatively few studies have characterized their venoms and evaluated their potential hazards for humans. Herein we explore the protein composition and properties of the venom of the rear-fanged Green Parrot Snake, Leptophis ahaetulla marginatus, the most common snake found in the Iguazu National Park (Argentina), as well as the main features of its venom delivery system. This species has venom reminiscent of elapid venoms, composed mainly of components such as 3FTxs, CRiSPs and AChE, but it shows low toxicity toward mammals (LD50 > 20 μg/g mouse). The histology of its Duvernoy's venom gland is similar to that of other colubrids, with serous secretory cells arranged in densely packed secretory tubules. The posterior end of its maxilla exhibits 1-3 blade-shaped and slightly recurved fangs but without grooves. This study provides an initial analysis of the biological role of venom in Leptophis, with implications for potential symptoms that might be anticipated from bites by this species.