ORIGINAL ABSTRACT

Cameroon rainforest region is not only an agricultural area with massive pesticide uses but also possesses factors that favor land snails' growth like Archachatina marginata. The present study aimed to assess the impact of sub-chronic exposure of commonly used pesticides in Cameroon, glyphosate, metalaxyl, and cypermethrin on the growth, survival, histological structure of key organs, and tissue residue levels in Archachatina marginata. Therefore, sub-adult (under 30 g) Archachatina marginata snails were exposed for 10 weeks, once a week to field-relevant concentrations of glyphosate (0.5 g/L), metalaxyl (3.3 g/L), and cypermethrin (2 g/L), while the control group was exposed with tap water. The experiment was repeated four times. Survival and body weight were recorded weekly. Post exposure, tissue residues were analyzed by GC-MS, and histological examinations of the kidney and ovo-testis (snails' gonad) were performed. The result showed no significant differences in the survival or external morphology of exposed snails. However, deeper statistical analyses revealed that snails exposed to metalaxyl had significantly lower final weights compared to all other groups with a mean loss of -8.7 g (-26.6%). A histological examination revealed visible alteration in the kidney and ovo-testis tissues of treated snails, though these changes could not be confirmed statistically. Moreover, pesticide residues were detected in the tissues of treated animals, with trace amounts of glyphosate and cypermethrin also found in control snails, likely due to prior contamination or cross-cage drift. In conclusion, sub-chronic exposure to field-used pesticides did not induce mortality in Archachatina marginata but did affect growth and tissue integrity, especially under metalaxyl exposure. These findings raise concerns about sub-lethal toxicity and food safety risks and support the use of Archachatina marginata as a bioindicator in pesticide-exposed environments.