Fish Rearing

Fish Rearing

1. "Give a man a fish and you feed him for a day, teach the man how to grow that fish and you feed him for life."

2. FISH REARING

3. Rearing Bring up and care for until fully grown

4. Fish Rearing Also known as fish farming Raising fish commercially in tanks or enclosures such as fish ponds, usually for food. Worldwide, the most important fish species produced in fish farming are carp, tilapia, salmon, and catfish.

5. Purpose of fish rearing Better use of land and water. Source of food for humans Source of income

6. Categories Fish farming may involve use of 1)local photosynthetic production (extensive) 2)fish that are fed with external food supply (intensive) 3)Both (semi intensive)

7. Intensive aquaculture Aimed for achieving maximum production of fish from a minimum quantity of water. Fishes are fed on artificial food. Relies on technology to raise fish in artificial tanks, ponds and raceways at very high densities.

8. Semi Intensive aquaculture Involves rather small ponds. Both natural and artificial food is provided.

9. Extensive Aquaculture Culture and rearing in which human intervention is concentrated on the reproduction of stock, in addition to capture. E.g. prawns, muscles, seaweed, carp, tilapia, tuna and salmon.

10. Characteristics Food supply : utilizes natural photosynthetic production of food (algae, plankton, molluscs , crustaceans) to feed them. Suitable Region: areas of coastal mangrove, swamps, marshes, estuaries. Stocking and production: low stocking densities.

11. Fish farms Cage system Copper-alloy nets Irrigation ditch or pond systems Composite fish culture

12. 1)Cage system Also known as "off-shore cultivation” when the cages are placed in the sea Placed in lakes, bayous, ponds, rivers, or oceans Fish are stocked in cages, artificially fed, and harvested when they reach market size. Advantages : Many types of waters can be used (rivers, lakes, filled quarries, etc.), many types of fish can be raised, and fish farming can co-exist with sport fishing and other water uses.

13. Giant gourami is often raised in cages in central Thailand

14. 2)Copper-alloy nets Important netting materials in aquaculture Are antimicrobial (destroy bacteria, viruses, fungi, algae, and other microbes) Copper-zinc brass alloys are deployed in commercial-scale aquaculture operations in Asia, South America, and the USA (Hawaii). Advantage: resistance of organism growth on copper alloy nets provides a cleaner and healthier environment for farmed fish to grow.

15. 3)Irrigation ditch or pond systems Use irrigation ditches or farm ponds to raise fish. Basic requirement is to have a ditch or pond that retains water, possibly with an above-ground irrigation system. In small systems, the fish are often fed commercial fish food. In larger ponds, the pond grows water plants and algae as fish food.

16. 4)Composite fish culture Comprise of a combination of both local and imported fish. Five or six fish species having different habitat are used in a single fish pond. E.g. catla and silver carp (surface feeders) rohu (column feeder) common carp (bottom feeders).

17. Factors effecting growth of fish Age Type of food Water temperature

18. 1)Age Embryo of fish grow more than the aged fish because of its efficiency being 58% as compared to that of aged fish which is 15% .

19. 2)Type of food Feeding on artificial food is less efficient as compared to feeding on natural food. Fishes feeding on high protein food grows well. Fishes feeding entirely on roughage will not grow well.

20. 3)Water Temperature Growth efficiency is higher in warm water as compared to cold water.

21. Issues Pollution Impact of Biodiversity Tilapia Takeover Spread of Disease & Antibiotic Use Pesticide Use

22. References https://en.wikipedia.org/wiki/Fish_farming http://biology.kenyon.edu/stures/Compsnelson/Aquaculturepage.htm https://www.slideshare.net/zeal_eagle/extensive-aquaculture https://wellnessmama.com/105599/fish-farming/ Lecture by Sir Zaigham Hassan

23. Thank you