-40). Las evaluaciones biométricas muestran que mayor crecimiento, conversión alimentaria y factor de condición se obtuvieron en A. scapularis alimentadas con la dieta DM-48 (P < 0,05). Sin embargo, la relación talla-peso y consumo de alimento-talla fueron similares entre los tratamientos dietarios. Por otro lado, menores concentraciones de proteína y mayores de lípidos se obtuvieron en el músculo de juveniles de A. scapularis alimentados con las dietas DM-48 y DF-50 (P < 0,05), respectivamente. El análisis de componentes principales mostró una mayor correlación entre peces alimentados con la dieta DM-48 y el contenido muscular de DHA, EPA y ARA; y con el crecimiento. Los resultados sugieren que la formulación de alimentos para juveniles de A. scapularis debería contemplar al menos de 48% de proteína y concentraciones importantes de DHA, EPA y ARA para su adecuado crecimiento de esta especie. Palabras clave: Anisotremus scapularis, Haemulidae, chita, ácidos grasos esenciales, maricultura.Evaluation of commercial diets on growth and its effect on muscle biochemical composition of juvenile Peruvian grunt, Anisotremus scapularis (Tschudi, 1846) (Familia: Haemulidae)ABSTRACT. The growth, muscle proximal composition and fatty acid profile of juveniles of Anisotremus scapularis fed with four commercial diets were evaluated. During 106 days, 200 fishes, were distributed in four treatments, fish were fed with commercial diets identified by their protein content: 50% (DF-50), 48% (DM-48), 44% (DT-44) and 40% (DT-40). Biometric evaluations showed that higher growth (P < 0.05), feedconversion and condition factor were obtained in A. scapularis fed with DM-48. However, both length-weight and food intake-size relationships were similar among dietary treatments. Lower (P < 0.05) protein and higher (P < 0.05) lipid concentrations in muscle of A. scapularis fed with DM-48 and DF-50 were obtained, respectively. Principal component analysis showed a higher correlation between fishes fed with DM-48 and DHA, EPA, and ARA muscle contents as with growth. Our results suggest that the food formulation for juveniles of A. scapularis should include at least 48% protein and significant concentrations of DHA, EPA and ARA for a proper growth of this species.