USE OF BIOFLOC TECHNOLOGY IN THE PRODUCTION OF THE Colossoma macropomum x Piaractus brachypomus HYBRID WITH A LOW PROTEIN DIET

The present study was carried out to observe the performance of the hybrid Colossoma macropomum x Piaractus brachypomus, when cultured in a Biofloc system. Six hundred fingerling with a mean weight of 3.3 +/- 0.4 grams (g), were randomly distributed into six concrete tanks (22 fish/m(3)). Three randomly selected tanks were routinely supplemented with molasses, as an extra source of carbohydrate (Mol) and the other three were only given feed (Feed) containing 28% protein, during 154 days. Water quality parameters such as: dissolved oxygen, total ammonia nitrogen, nitrite, nitrate, alkalinity, hardness and pH were in the accepted range for the specie in both treatments. Significance differences in final weigh, growth rate and final density were observed (P < 0.05) between treatments. In Mol treatment, fish grew to a final weight of 332.16 +/- 79 g, a feed conversion ratio of 1.27 +/- 0.06 and a survival rate of 97%. In Feed treatment, fish grew to a final weigh of 290.28 +/- 72 g, a feed conversion ratio of 1.31 +/- 0.06 and a survival rate of 93%. This work showed that the hybrid of C. macropomum x P. brachypomus can be grown in biolfoc systems without affecting its production yield.