<strong>Performance of fingerling of Nile tilapia (<em>Oreochromis niloticus</em>), gift, chitralada and bouake strains in hapas</strong> - DOI: 10.4025/actascianimsci.v30i3.455

Abstract

This essay aimed to evaluate the productive performance of three Nile tilapia (Oreochromis niloticus) strains, GIFT (Genetic Improvement of Farmed Tilapia), Bouake and Chitralada, during the production of juveniles from February to May, 2007. The sexually reverted fingerlings were stored in twelve 9 m3 hapas installed in a ponds with 0.7 ha water blade. At the end of 93 days of culture a significant change in survival among the three strains (P<0.05) was verified, where GIFT (96.80%) surpassed Chitralada (90.85%) and Bouake (77.74%). The average final weight (40.49; 34.53 and 32.42g), daily body mass gain (0.43, 0.37 and 0.34g day-1) and feed conversion (1.80 1.81 and 1.81) did not present significant differences among GIFT, Bouake and Chitralada, respectively. The GIFT final biomass (19,594.79g) surpassed Bouake (19,528.85g) and Chitralada (16,488.99g), not differing statistically, though (P>0.05). The average of fish weight more than 25g was over 80% of the lots, which guaranteed the juvenile uniformity and standardization. The toxic metals cadmium and lead were above the tolerable level in the fish, although the chromium metal was not detected. The GIFT strain presented the best performance in this culture system, although it contained high indexes of heavy metals in comparison with the other two strains.