Alimentação e comportamento de pós-larvas de pacu, Piaractus mesopotamicus (Holmberg, 1887)

Abstract

The objective of this reserch was to evaluate the effects of natural and artificial diets on the development of pacu (Piaractus mesopotamicus) post-larvae, between the 2nd and 10* day post hatch, and they behavior. The post-larvaes were kept in 30L - plastic boxes (n = 30 boxes), in constant flowthrought. The post-larvae density was 10 post-larvae/L (300 post-larvae/box). Six diets with 4 sampling days (4, 6, 8 and 10 days post-hatch, n = 30 post larvae) and 5 repetitions were tested. The diets were: TI- commercial feed, T2- plancton, T3- artêmia, T4- plancton + feed, T5- artêmia + feed and T6- artêmia + plancton. Post-larvaes were fed 6 times a day: 4:00, 8:00, 12:00, 16:00, 20:00 and 24:00 hours. The water temperature was kept constant at 27°C, dissolved oxigen was kept above 6.16 ± 0.34 and pH between 6.94 ± 0.22 and 7.38 ±0.18. At the end ofthe experiment (10* day post-hatch), the post-larvaes that received diet containing artêmia + plancton (T6) were longer (8.35 mm) and heavier (3518 μg body weight), compared to the post-larvae fed with the other tested diets. The post-larvae should be in the laboratory for 6 days after hatch and receive from the 3"1 day after hatch.