EFFECT OF THE DIETARY INCLUSION OF DECAPSULATED ARTEMIA CYSTS ON GROWTH AND SURVIVAL OF RED TILAPIA (OREOCHROMIS MOSSAMBICUS) FRY AND ITS SUBSEQUENT FINGERLING PRODUCTION

摘要

Red tilapia fry Oreochromis mossambicus (6.3 mm and 0.008 g mean standard length and wet weight, respectively), was reared after yolk absorption, using 10-L plastic containers (n = 40 fish per container) in a closed recirculation system. Five diets were tested with three replicates: 100% tilapia starter diet (TS100), 75% tilapia starter diet + 25% decapsulated Artemia cysts (75TS/25DAC), 50% tilapia starter diet + 50% decapsulated Artemia cysts (50TS/50DAC), 25% tilapia starter diet + 75% decapsulated Artemia cysts (25TS/75DAC), and 100% decapsulated Artemia cysts (100DAC). Diets were given ad libitum four times a day for the first 30 days after yolk absorption. Then, fingerlings from each hatchery diet were fed in excess with theTSI 00 diet for thenext 30 days, in a flow-through system. Mean standard length and wet weight were determined every 10 days for the first experimental month, and at the end of the second 30 culture days. Final specific growth and survival were also recorded. Larvae fed on the TS/DAC-mixed hatchery diets produce fry and fingerlings heavier than the 100TS and 100DAC groups in both experimental phases. Fry from the 25TS/75DAC treatment obtained the highest weight value (1.86 g) after the first 30 days of exogenous feeding,and fingerlings from the same group weighed 14.96 g in average individually, after 60 culture days from the yolk sac absorption. Final survival fluctuated from 80% for the 100DAC group, to 90% for the 50TS/50DAC treatment. Since there were no differences (P > 0.05) in growth among theTS/DAC groups, the inclusion of at least 25% of DAC in the hatchery diet of O. mossambicus is suggested to improve its growth performance. Before application of DAC at commercial level, technical and economical considerations should be carefully reviewed.