Compensatory growth of juvenile matrinxã Brycon amazonicus (Spix & Agassiz, 1829)
The objective of this work was to study the compensatory growth in juveniles of matrinxã Brycon amazonicus. The fish (16g) were randomly distributed in nine tanks and submitted to different feeding protocols: control - fish were fed ad libitum for 60 days, J10 (fast for 10 days) - fish were fed ad libitum for 10 days, fasted for 10 days days, and again fed ad libitum for 40 days, J20 - fish were fasted for 20 days and fed ad libitum for 40 days. Six fish from each treatment (two from each tank) were sampled at the beginning of the experiment, at the end of the fasting period, and at the end of the experiment for growth and biochemical analysis. The results obtained in this study showed a total compensatory growth of matrinxã juveniles fasting for 10 or 20 days,as evidenced by the similar final weight among fish from all treatments. Although not significant, there was a trend towards weight gain, specific growth rate and feed efficiency for fasting fish, compared to control. Daily feed intake was slightly higher for control fish and total feed intake was lower for fasting fish. The stocks of glycogen and glucose, protein and plasma triglycerides were not affected during dietary restriction, showing good tolerance of matrinxã juveniles for at least 20 days of fasting. Compensatory growth is fully achieved, and there is a 37% reduction in feed consumption for fasting fish for 20 days compared to control, an important issue for intensive fish farming.