Abstract:
Indoor experiments were conducted to examine growth performance and biochemical response of Nile tilapia (Oreochromis niloticus) and lettuce (Lactuca sativa) to spirulina (Arthrospira platensis) enhanced aquaponic system. The effect of spirulina enhanced aquaponic system on growth, feed utilization, haematological parameters and whole-body composition of O. niloticus was determined. The effect of spirulina stimulant on growth and antioxidants content of L. sativa in aquaponic system were determined. Measurements were done to determine the effect of spirulina enhanced aquaponic system on water quality variables and nutrient concentration. A one-way analysis of variance (ANOVA) was used to determine the treatment effect and whenever the effects of the treatments were significant (p ≤ 0.05) means were compared using Turkey’s test. Polynomial Contrasts were further used to determine the linear, quadratic and cubic effects of spirulina levels on O. niloticus, lettuce and water quality variables. Polynomial contrasts analysis showed that the cubic trend for growth, feed utilization and whole-body composition were significantly (p <0.05) increased by inclusion of 8 g of spirulina/kg of the basal diet. The contrasts analysis showed significant (p <0.05) linear increment for haematological parameters of O. niloticus. The contrasts analysis showed significant (p <0.05) linear increment for dry weight and antioxidant contents with a peak at 12 g of spirulina/kg of the basal diet. The contrasts analysis showed significant (p <0.05) linear increment for total nitrate and phosphate retention.
Key words: Aquaponic; spirulina; Oreochromis niloticus; haematology; antioxidants, Lactuca sativa.
