Periphyton Technology Enhances Growth Performance and Delays Prolific Breeding of Nile Tilapia, Oreochromis niloticus (Linnaeus, 1758), Juveniles

Abstract

This study evaluated the effect of periphyton technology (PPT) on the growth performance and breeding schedule of Oreochromis niloticus (Linnaeus, 1758) juveniles. Six ponds, each measuring 81 m2 were used for the study. The ponds were applied with agricultural lime at a rate of 4 g.m-2, and fertilised using chicken manure to facilitate primary productivity. The PPT ponds were fitted with two-metre-long eucalyptus poles of 5 cm diameter placed at 50 cm intervals with the regular addition of molasses as a carbon source. Tilapia juveniles were stocked at a density of 3 fish.m-2 in all ponds and fed on a commercial diet of 20 % crude protein (CP) twice daily at 3 % body weight. Fish were sampled weekly for growth and survival data and bi-weekly for fecundity estimates. The PPT-ponds registered significantly higher survival rate (97.50 ± 0.35 %), mean weight (150.69 ± 0.99 g), specific growth rate (SGR) (2.75 ± 0.01), and feed conversion ratio (FCR) (1.29 ± 0.01), than the control ponds, which registered survival (91.15 ± 0.88 %), mean weight (99.23 ± 0.96 g), SGR (2.29 ± 0.00), and FCR (1.58 ± 0.01). There was significantly higher fecundity in the PPT-ponds (2.28 ± 0.09 g.fish-1) than control (1.74 ± 0.06 g.fish-1), with prolific spawning starting 4 weeks earlier in the control ponds than in the PPT-ponds. This study demonstrated the potential of PPT for enhancing tilapia growth while delaying prolific breeding behaviour. Further studies should explore PPT in replacing synthetic hormones for sex-reversal of tilapia fry in hatcheries.