Effects of food sources on growth rates and survival of Nile tilapia (Oreochromis niloticus) fry

The present study was conducted to investigate the effects of live food (Chlorella vulgaris, Artemia fransciscana), artificial feed and combinations of both types (Chlorella + Artemia nauplii; Chlorella + Artificial feed; Artemia nauplii + Artificial feed; and Chlorella + Artemia nauplii + Artificial feed) on the growth, feed utilization efficiency and survival of Nile tilapia (Oreochromis niloticus) fry. Triplicate groups of swim-up fry (0.012 g average body weight) were stocked in 20 l fibreglass tanks, with 6 l of water, in a closed rectangular indoor system, at a density of 24 fry per tank (4 fry l ^-1). The foods were offered to the fish 3 times a day, for 35 days. The results indicated that the maximum body weight gain and survival were achieved in fry fed on Artemia nauplii and on the combination of the three food types, followed by those fed on Artemia nauplii + Artificial. The lowest growth and survival rates were observed in fry fed on Chlorella suspension alone. The fry fed only with artificial feed showed moderate growth and good survival. In conclusion, Artemia nauplii was the best live food, followed by Artemia nauplii combined with artificial feed, to accelerate the growth rate of the fry.