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...

Oral Acute Toxicity and Genotoxicity of Heteroctenus junceus Scorpion Venom

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Oral Acute Toxicity and Genotoxicity of Heteroctenus junceus Scorpion Venom

ABSTRACT

Objective

The study evaluates the elemental composition, oral acute toxicity, genotoxicity, and mutagenic potential of Heteroctenus junceus scorpion venom.

Methods

The elemental composition was determined by atomic absorption spectrophotometry and HPLC-MS/MS. The acute oral toxicity test was assessed in mice at 300 and 2000 mg/kg. The in vivo micronucleus test was conducted in mice treated with three scorpion venom doses (10, 100, and 1000 mg/kg). Meanwhile, the in vitro micronucleus test was conducted in TK6 cells treated with three scorpion venom doses (1.25, 2.5, and 5 mg/mL). The Ames test followed the OECD guidelines, and various scorpion venom concentrations (0.16, 0.32, 0.63, 1.25, 2.5, 5 mg/mL) were used.

Results

The elemental analysis of scorpion venom reveals the lowest amino acid and elemental composition levels compared to other species. An LD50 value greater than 2000 mg/kg was obtained in the oral acute toxicity test with transient pathophysiological effects in the liver, lung, and kidney at 300 and 2000 mg/kg. The in vitro micronucleus test showed that the negative control and scorpion venom concentrations did not induce micronuclei in TK6 cells. Meanwhile, the in vivo micronucleus test showed an increase in the frequency of micronucleated polychromatic erythrocytes and a dose-dependent decrease in erythrocyte count only at doses higher than 100 mg/kg. The Ames reverse mutation test did not show an increase in revertant colonies in the scorpion venom-treated groups compared to the negative control.

Conclusions

H. junceus venom has a low toxicological potential.

Díaz-García, A., Ruiz-Fuentes, J. L., Medina, S. M., Guajardo, N. Z., & Skarneo, C. R. (2026). Oral Acute Toxicity and Genotoxicity of Heteroctenus junceus Scorpion Venom. Veterinary Medicine and Science, 12(2), e70872. https://doi.org/10.1002/vms3.70872