"Macrobrachium tenellum is a freshwater prawn native from Mexico to Peru, with potential for cultivation. Currently, it is extensively exploited by local fisheries. To understand its chitin requirements, a formulated diet with chitin added (5, 10 15, 20, and 25%) was given to juveniles for 60 days. Growth, survival, and enzyme activity (trypsin, chymotrypsin, lipase, amylase, and chitinase) were measured every 15 days. Highest final weight and specific growth rate resulted from diets with 20% chitin. Poorest performance resulted from diets with 5 and 10% chitin. Chitin in the diet did not have a significant effect on survival. Statistically significant differences in enzyme activity were not found in any treatment."