Efecto de la adición del rotífero Brachionus rotundiformis (Tschugunoff, 1921) sobre la calidad del agua y la producción, en cultivos super-intensivos de camarón blanco del Pacífico Litopenaeus vannamei (Boone, 1931)

The effectiveness of the rotifer Brachionus rotundiformis as exogenous natural feed combined with balanced feed on the production parameters of Litopenaeus vannamei and the water quality was evaluated. Different concentrations of rotifers were tested (0, 5, 10, 15 and 20 rotifers mL^-1) during 45 days. No significant differences were assessed in the phosphate levels among treatments. The pH level was statistically lower in the treatments with 15 and 20 rotifers mL^-1. Nitrate, nitrite and ammonia were significantly lower in the treatments with low concentration of rotifers (0 and 5 mL^-1), while the highest values were achieved in the higher concentrations (15 and 20 mL^-1) without reaching toxic levels. The weight gain, biomass, survival and specific growth rate of L. vannamei were significantly higher in the treatments with the higher number of rotifers (15 and 20 mL^-1), whereas the lowest values were found in the control treatment (0 mL^-1). The feed conversion ratio (FCR) was statistically lower in the treatment with the highest concentration of rotifers, while the highest FCR was found in the control. It is concluded that the use of the rotifer B. rotundiformis in high concentrations improves the production parameters on the Pacific white shrimp, without deteriorating the water quality.