# Comparative Effects of Snake Envenomation on Rabbit Carcass Decomposition and Insect Succession in a Forensic Context

## TL;DR

This study shows snake venom changes how rabbit carcasses decompose and affects insect activity, which is important for estimating time of death in forensic cases.

## Contribution

The study reveals venom-specific effects on decomposition and arthropod succession, suggesting adjustments to forensic models for snake envenomation cases.

## Key findings

- C. cerastes venom accelerated early decomposition stages and altered arthropod abundance.
- Venom envenomation significantly changed decomposition dynamics compared to controls.
- PMI estimations may need venom-specific adjustments in forensic entomology.

## Abstract

This study investigates the effects of envenomation with venom from the horned viper (Cerastes cerastes) and the Egyptian cobra (Naja haje) on rabbit carcass decomposition and the succession of necrophagous arthropods, a critical component of forensic entomology. Compared with the control group, snake envenomation shortened the fresh and bloated stages of decomposition and reduced overall arthropod abundance. Notably, C. cerastes venom produced more significant alterations than N. haje venom. The findings demonstrate that snake venom significantly influences insect succession patterns and carcass decomposition dynamics. These results indicate that postmortem interval (PMI) estimations in snake envenomation cases may require venom-specific adjustments to standard forensic entomological models.

Background: Snake envenomation represents a significant health concern in some regions of the world, with fatal cases occasionally requiring forensic investigation to estimate the postmortem interval (PMI). However, the influence of venom on carrion decomposition dynamics and arthropod succession patterns remains poorly understood, potentially compromising postmortem interval (PMI) estimations in such cases. Objectives: This study investigated the effects of Naja haje and Cerastes cerastes venoms on decomposition progression and necrophagous arthropod succession. Methods: Fifteen rabbits were allocated into three experimental groups. Two groups received median lethal intravenous doses (LD50) of N. haje or C. cerastes venom, whereas the control group received a saline injection followed by CO2 euthanasia. The carcasses were subsequently placed under natural field conditions and monitored daily for 15 days. Results: The presence of venom significantly altered decomposition dynamics. C. cerastes venom accelerated early decomposition, shortening both the fresh stage (1 ± 0.22 days vs. 2 ± 0.31 days in controls,) and bloating stage (3 ± 0.35 days vs. 5 ± 0.35 days), while extending both the decay stage (6 ± 0.3 days vs. 6 ± 0.17 days) and the dried stage (5.0 ± 0.44 days vs. 2 ± 0.039 days). N. haje venom showed intermediate effects. Overall arthropod abundance peaked on day 5 and declined thereafter. Control carcasses exhibited significantly higher arthropod abundance than carcasses envenomed with C. cerastes or N. haje. Conclusions: Snake envenomation significantly influenced decomposition kinetics and arthropod colonization patterns. Envenomation with C. cerastes venom produced more pronounced alterations than envenomation with N. haje venom.