Enhancement of Reproductive Performance of Nile Tilapia Oreochromis niloticus using Phytobiotic Spirulina platensis

Background and Objective: Phytobiotics as additives in aquaculture feed are increasingly recognized as feed for young and adult fish.Spirulina improves digestion and direct fats in the fish to growth.The beneficial effect of inclusion of Spirulina platensis as feed additives in tilapia diets during their development was studied to estimate its effect on tilapia reproductive performance. Materials and Methods:A phytobiotic Spirulina platensis was introduced to tilapia feed for 19 weeks at concentrations of (0.5, 7.5, 10 and 20 g kgG 1 Spirulina platensis diet named: S 0 , S 5 , S 7 .5 , S 10 and S 20 , respectively).One hundred fish were divided to 5 groups and fed diets supplemented with algae at variable levels as well as control.The gonadosomatic index (GSI), fecundity, percentage of spawned eggs, egg and fry qualities were evaluated.Data were analyzed using one-way analysis of variance (ANOVA) at significance of (p<0.05).Results: Fish weight, GSI, spawning activity and spawned eggs number showed significant increase (p<0.05) on higher supplementation of phytobiotics and also fry length and weight increased in all the groups tested compared to control.Fry mortality and deformations percentage showed significant decrease (p<0.05) in phytobiotic fed fish.Group supplemented with algal level of (20 g kgG 1 Spirulina platensis diet) in their feed spawned earlier at 45.3±7.8 days compared to 49.5, 51.3, 54.1 and 66.7 days for fish fed the 10, 7.5, 5 g kgG 1 Spirulina platensis diet and control, respectively.Also, percentage of spawned eggs, total number of eggs/female recorded significant increase (p<0.05) in groups of fish supplied with the 20 and 10 g kgG 1 Spirulina platensis diet.Eggs diameter, volume as well as weight showed insignificant change, while hatchability percentage increase in Spirulina fed fish compared to fish receiving control diet.Conclusion: Inclusion of Spirulina in fish feeds improve reproduction performance of tilapia fish, suggesting that Spirulina is an appropriate reproduction-stimulating additive in Nile tilapia culture.