Submitted to: Aquaculture America Conference
Publication Type: Abstract Only
Publication Acceptance Date: 1/28/2002
Publication Date: N/A
Technical Abstract: Nile tilapia, Oreochromis niloticus, are popular food fish and culture fish. Small operations have begun raising Nile tilapia indoors for local markets and are often associated with hydroponic culture of herbs and vegetables. Two strains of Nile tilapia were evaluated in a greenhouse recirculating aquaculture system (RAS) consisting of six polyvinyl circular tanks with a culture volume of 540-L. Water gravity drained from the tanks into a 1200-L settling tank. Water from the settling tank was pumped through a 0.06 m3 bubble-washed bead filter at a flow rate of 90 Lpm. Three tanks were stocked with mixed-sex Nile tilapia and three tanks were stocked with genetically male tilapia (GMT). Initial stocking density in each tank was 100 fish with an average weight of 38 g. All tanks were fed with a 32% protein floating catfish pellet. Daily feed rate ranged from 2 to 4% body weight per day. After 73 days the fish were harvested. The average weight of the GMT strain of tilapia were 172 g. The average weight of the mixed-sex tilapia were 156 g. The GMT strain tilapia also displayed better feed conversion rates.