EFEECT OF DIFFERENT MICROALGAE ON GROWTH, SURVIVAL, WATER QUALITY AND NUTRITIONAL COMPOSITION ON JUVENILE TILAPIA (Oreochromis niloticus)

Abstract

In the present study, two selected marine microalgae were combined to produce a high-performing feed for Nile tilapia (Oreochromis niloticus)—the world’s second largest group of cultivated fish. In this study, a feeding trial was conducted with fry of Nile Tilapia Oreochromis niloticus in which two types of microalgae such as Tetraselmis chuii and Nannochloropsis sp. were used for replacement of fish meal protein. Seven experimental diet containing two microalgae were formulated to replace 0%, 25%, 50% and 75% of fish meal where each assigned to three replicate tanks, and each tank was stocked with 30 fry of Nile Tilapia from their first feeding for 22 days indoor feeding trial. The results of this study showed that two experimental diet T50% and N75% were performed significantly (P < 0.05) to obtain high weight gain / better growth than the formulated feed with 100% fish meal. Survival rate was found significantly (P < 0.05) higher in all treatments than control. SGR and water quality were also significantly (P < 0.05) higher than the formulated diets. In addition, the protein, lipid and carbohydrate content in Nile Tilapia fry reared in tanks with T50% and N75% were higher than for fry grown in control tanks. Therefore, this study suggests that Nile Tilapia fry reared in tanks can gain nutrition from the selected microalgae. Moreover, the presence of microalgae in the tanks has also been shown to maintain low level of TAN and nitrite in the culture system. Thus, microalgae used as feed supplement practice in hatcheries can be considered as a viable technology. Hence, selected marine microalgae could be used as feed supplement in enhancing the growth and survival of Nile Tilapia fry.