Growth, Survival and Nutrient Utilization of Nile Tilapia (Oreochromis niloticus) using Cyanophyceae (Arthrospira fusiformis) as Replacement of Fishmeal Based Diets

Suitability of using cynaophyceae (Arthrospira fusiformis) to replace fishmeal (Caridina nilotica) as a main protein source in the diet of Nile tilapia (Oreochromis niloticus) was investigated at a ratios of: 25 %, 50 %, 75 % and 100 %. The five dietary treatments were tested in triplicate in static earthen ponds for 160 days. Growth, Food conversion ratio (FCR), and nutrient utilization in fish fed at 25 % and 50 % A. fusiformis were better than those fed 75 % and 100 % A. fusiformis but not significantly different (P greater than 0.05) from those fed with C. nilotica diets alone. Growth reduction, increased FCR and reduced nutrient utilization occurred with increasing A. fusiformis in the diet beyond 50 % inclusion levels. Survival was however better at higher levels of A. fusiformis inclusion. Thus it is possible to replace up to 50 % of C. nilotica with A. fusiformis in the diets of O. niloticus.