diets were formulated to contain three contents of protein and two relative carbohydrate contents. A 3×2 factorial design with three replicates per dietary treatment was used in this study. Diets were prepared with the ingredients indicated in Table 1. The feed formulation model was developed using an Excel software (Table 2) with the following factors and contents: three protein contents (20, 30 and 40%) and two carbohydrate contents (low: from 16.3 to 23.5% referred to as: “C low” and high: from 34.6 to 35.8%, named as: “C high”) (Table 3). Selected ingredients and prepared diets were analyzed at UC Temuco Aquaculture Department in the Nutritional Laboratory according to the Official Methods of Analysis (AOAC, 1998).