Apparent Control of Sexual Differentiation of Freshwater Prawn,Macrobrachium rosenbergii,Through Dietary Administration of Dopamine Hydrochloride

ABSTRACT

Dopamine at concentrations of 0.15, 1.5, and 15.0 mg/kg was included in two different formulated diets that were fed to recently metamorphosed postlarvae of the freshwater prawn, Macrobrachium rosenbergii, for 60 days. Dopamine, in the form of dopamine hydrochlo-ride, was incorporated into the formulated diets by either solubilizing it in alcohol, followed by submersion of diet and evaporation, or inclusion in a lipid premix ingredient. The alcohol evaporation method at 0.15, 1.5, and 15.0 mg/kg significantly increased the percentage of individuals without external male characteristics. This research is the first reported use of dietary administration of dopamine to crustaceans, and the first documentation of the apparent dietary control of gonadal development and sex differentiation in crustaceans. Replication of results, a histological examination of a large sample of individuals, and continued monitoring of those individuals fed the dietary dopamine are needed to verify the apparent effect.