Effect of feeding Spirulina platensis on growth and carcass composition of hybrid red tilapia (Oreochromis mossambicus × O. niloticus)

The present study was designed to evaluate the use of spirulina (Spirulina platensis) as a protein source for hybrid red tilapia. Spirulina was incorporated into four isonitrogenous and isocaloric diets at 0, 5, 10 and 20% of the fishmeal-based diet. The test diets were fed to the fish at 2% body weight twice a day for 120 days. The final weight gain, specific growth rate, feed conversion ratio and survival rate of fish were not affected by spirulina supplementation (p>0.05). There was no significant difference (p>0.05) in carcass proximate composition of the fish fed on spirulina diets as compared to those on control diet. This study demonstrates that up to 20% of spirulina can be substituted for fishmeal in a fishmeal-based diet for hybrid red tilapia without any adverse effect on fish growth.