Impact of pesticides exposure on Archachatina marginata snails in four Cameroon monomodal rainforest sites

Abstract

Cameroon monomodal rainforest zone has a strong agricultural activity and is therefore exposed to pesticides. Furthermore, the area possesses climatic factors that favor the growth of Achatinadea snails known as African giant snails, a delicacy for the local population. The present study aimed to evaluate pesticides contamination (less vs more exposed areas) through assessment of exposure and impact on Achatinadea snails. Achatinadea snails were collected within intensive agricultural areas (Njombe and Kribi rural) and in areas with less agricultural activity (Ebodje and Dibombari). Collection was performed at night between July and September 2020 using an adapted square kilometer method. Type, number, weight, and size of the collected snails were analyzed and compared using Welsh’s One-way Analysis of variance (ANOVA). After removing the soft part from the shell, the presence of pesticides was determined using mass spectrometry. Histological analysis of kidney and ovo-testis was performed using eosin-hematoxylin staining. Results showed that the main variety of snails collected are Archachatina marginata. In areas with less agricultural activity, snails are bigger than those from more agricultural areas heavily using pesticides. Furthermore, pesticides detection showed that glyphosate, but not metalaxyl, is present in animals coming from all the collection sites. Cypermethrin was found in all the samples except in those from Dibombari. Histology revealed that the structure of the kidney and ovo-testis of snails from more exposed areas is impaired. In conclusion, this study revealed that some pesticides are transferred to snail and impair the structure of important organs.