1. Fish Selection for Tank Culture and Feeding Systems Gary J. Burtle University of Georiga Animal & Dairy Science Tifton, GA gburtle@uga.edu 229-386-3364

2. Feeding Indoor Tanks Absolutely need a complete feed –Also needs to be digestible May supplement with natural food or vitamin-rich products Feed every day, or multiple times/day Use lighting to grow algae on tank sides

3. Some Food Items Natural foods –Fly larvae, worms, brine shrimp, meal worms Ground meat –Beef liver, egg yolk, shrimp, fish paste Yeast –Brewers, specialty Food waste - vegetable Fertilizer – for greenwater or biofloc

4. Live Food Culture

5. Brine shrimp for small fish Aeration and a light source are required. Salt water to hatch cysts.

6. Artificial Feed for Small Fish 50% protein, small particle, Zeigler Finfish Feed

7. Tilapia Fingerlings in Tank With Clear Water

8. Tilapia Nutrient Requirements 25 to 30% protein Can use plant materials effectively Fiber should be kept low Fat should contain linoleic (n-6) fatty acids, about 1% of diet A complete vitamin and mineral supplement is needed for tank culture

9. Bluegill Nutrition Notes Natural diets contain about 20% plant material Large zooplankton, insects and crustaceans make up most of the diet Therefore, bluegill are carnivorous –A relatively high protein (35 to 40%) and high fat (10 to 15%) diet is recommended

10. Catfish Nutrient Requirements Protein Fiber Vitamin C Other Vitamins Minerals Note: Stock at >8 catfish per cubic foot 28 to 36% > 4% 80 mg/kg Stable C Complete (12 items) P, Zn, Co, Cu, I, Se, Mg, Fe, Ca

11. Potential Bluegill Diets ZieglerSilverRangen400Aquamax500 Silver Cup Protein40414140 Fat10121212 Fiber454- Ash8810-

12. Bream Growth in Recirculating System, 200 days (7 months) 1/3 lb

13. Growth of Israeli Hybrid Tilapia (pounds over weeks) 1.3 pounds of gain In 200 days

14. Tilapia Feeding System Green water or small pellet feed for first three months Supplement with a 28% protein feed for final 3 months Feed conversion is expected to be 1.5 pounds of feed per pound of fish and could be better

15. Hybrid Tilapia at 800/1200 gal

16. Green Water Culture

17. What is Green Water? Usually a blue-green algae/water mixture Needs open air or greenhouse environment Nitrogen and phosphorus provided by feed or fertilization Other systems (“green manure”) –Duckweed –Azola water fern

18. Tilapia in Green Water Green water provides a basis for nutrition, usually for smaller stages of fish Prepared feed is used to finish the fish later in the growing season –Feed quality and cost can be lowered by the presence of green water

19. System Requirements to use Green Water Light from the sun or grow lights Heat source for the water Aerating system Sediment collection system

20. Simple Culture Tank and Sludge Removal Tank

21. Partitioned System for Catfish/Shrimp and Tilapia Catfish Area Tilapia Area

22. Production from PAS Tilapia in two 8 ft compartments of the system (0.33 acres) Stocked at 400 to 800 per compartment Resulted in about 1,000 pounds of Tilapia Reduced aeration requirement and improved water quality for catfish/shrimp production (6,000 pounds of catfish) Algae was reduced from >100 mg/L to about 50 mg/L by Tilapia (less blue-green)

23. Exposed Tilapia Tank with High Rate Aeration BIOFLOC PRODUCTION = BROWN WATER

24. What is Biofloc? Each floc is held together in a loose matrix of mucus that is secreted by bacteria, bound by filamentous microorganisms, or held by electrostatic attraction. also includes animals that are grazers of flocs, such as some zooplankton and nematodes. NEEDS A HIGH RATE OF AERATION.

25. Bacteria, algae, protozoa

26. The effects of feeding tilapia increasing levels of DUCKWEED. Tilapia were held in static water in concrete tanks (Hassan and Edwards 1992). The fish initially weighed approximately 41g Feeding rate LemnaSurvival rateMean LW gainConversion (g DM/kg fish)of fish (%)(g/d)of Lemna DM to fish live- weight (g/g) 10970.21.9 201000.41.9 301001.01.6 40601.02.3 50270.73.3 60170.83.3

27. Bottom Line Use green water to reduce cost Stock the fish that you can sell at a good price Use supplemental feeds to finish out the fish Tilapia still are the best candidate for tank culture as food fish But, less regulation of bluegill or catfish.