author(s)
Castro Mejia Germán, Castro Mejia Jorge, Tinoco Pérez Laura Irlanda and Salvat Navarrete Kenia Alejandra

abstract
In the present study, the efficiency of the microalgae Scenedesmus sp. and Pinnularia sp. as a supplement in the diet of tilapia was tested in the growth in size and weight of Pargo tilapia, UNAM, cultured in a Biofloc in 250 L containers, in a period of 120 days. Survival of the organisms in the three treatments ranged from 80-85%. Organisms in the 10 cells x 10⁶ treatment obtained the highest weight with 598±0.60 g, although the highest length gain was found in the control treatment with 41.06 cm. The AGR for weight was higher in the 10 cells x 10⁶ treatment with 4.74 g day^-1, while the highest IGR for length was presented in the control treatment with a 0.33% daily increase. For length, the highest AGR was for the 10 cells x 10⁶ treatment with 4.58 g day^-1 and the IGR was for the 2.5 cell x 10⁶ treatment with 2.59% daily increment. Both FCF and FCE were for the 10 cells x 106 treatment with 0.247 and 404.5%, respectively. The incorporation of microalgae into the system provides nutrients that the Biofloc and bacterial biomass do not incorporate in the diet of the organisms.