The metabolism of atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine] in box crabs (Sesarma cinereum) was determined. Leaves of smooth cordgrass (Spartina alterniflora Loisel) collected from plants for 2 days in nutrient solution containing [14C] atrazine, followed by 3 days in an atrazine-free nutrient solution, were fed to box crabs for 10 days. No significant effects of atrazine on the behavior or survival of crabs were found. At the end of the 10-day feeding period, crabs and their feces were extracted with 80% methanol, and the extracts were concentrated and partitioned with chloroform. Radioactivities in the chloroform, aqueous, and 80% methanol-insoluble fractions (remaining crab material) of the extract were 7, 86, and 7% for crabs and 25, 51, and 24% for feces, respectively. Only 1.2 and 0.5% of the total radioactivity in the crab and feces, respectively, was atrazine, compared to the S. alterniflora used as a food source that contained 24% atrazine. This indicates that atrazine is metabolized in the crab. The accumulation of water-soluble metabolites in the crab suggests that, as in other animals, glutathione conjugation or a comparable pathway is responsible for the almost complete degradation and detoxification of atrazine in these organisms.; The metabolism of atrazine left bracket 2-chloro-4(ethylamino)-6-(isopropylamino)-s-triazine right bracket in box crabs was determined. Leaves of smooth cordgrass (Spartina alterniflora Loisel) collected from plants grown for 2 days in nutrient solution containing left bracket **1**4C right bracket atrazine, followed by 3 days in an atrazine-free nutrient solution, were fed to box crabs for 10 days. No significant effects of atrazine on the behavior or survival of crabs were found. At the end of the 10-day feeding period, crabs and their feces were extracted with 80% methanol, and the extracts were concentrated and partitioned with chloroform. Radioactivities in the chloroform, aqueous, and 80% methanol-insoluble fractions (remaining crab material) of the extract were 7, 86, and 7% for crabs and 25, 51, and 24% for feces, respectively. Only 1. 2 and 0. 5% of the total radioactivity in the crab and feces, respectively, was atrazine, compared to the S, alterniflora used as a food source that contained 24% atrazine. This indicates that atrazine is metabolized in the crab.
