DIETARY SPIRULINA (Arthrospira platensis (Gomont) Geitler, 1925) REPLACEMENT ENHANCES PERFORMANCE OF POND- AND TANK-REARED JUVENILE NILE TILAPIA (Oreochromis niloticus Linnaeus, 1758)  

A feeding trial was conducted to evaluate the effects of Spirulina (Arthrospira platensis) inclusion in experimental diets of juvenile Nile tilapia (Oreochromis niloticus). Iso-nitrogenous and iso-lipidic diets were pre- pared using a positive control diet (S0) and four basal diets with A. platensis at 30% (S30), 45% (S45), 60% (S60), and 75% (S75) inclusion levels. Experimental diets were randomly assigned to tanks (13.35 kg m^-3) with initial body weight of 0.89 ± 0.02 g in triplicates. The results of the feeding trial demonstrated significantly improved (P < 0.05) growth performance and hepatosomatic and viscerosomatic indices of fish fed S30. Blood chemical profile also indicated desirable values in fish fed A. platensis diets as compared to fish fed S0. On the contrary, fish fed S75 exhibited significantly reduced fish growth. Blood chemical analysis showed significant difference (P < 0.05) in levels of plasma triglyceride. Results of the present work indicate that 30% A. platensis inclusion is deemed the optimal level of dietary replacement for increased growth performance, improved feed utilization efficiency, and enhanced overall health status of Nile tilapia juveniles.