Editing Fish farming (section)

==== Composite fish culture ====
The composite fish culture system is a technology developed in India by the [[Indian Council of Agricultural Research]] in the 1970s. In this system, of both local and imported fish, a combination of five or six fish species is used in a single fish pond. These species are selected so that they do not compete for food among them by having different types of food habitats.<ref>{{cite web|url=http://www.fao.org/docrep/field/003/AC229E/AC229E07.htm|title=Lecture Notes on Composite Fish Culture and its Extension in India|access-date=30 January 2016}}</ref><ref>{{cite web|url=http://harfish.gov.in/technology.htm|archive-url=https://web.archive.org/web/20170309061425/http://harfish.gov.in/technology.htm|url-status=dead|archive-date=2017-03-09|title=Ornamental Fish Breeding|publisher=Fisheries Department Haryana, Chandigarh, India}}</ref> As a result, the food available in all the parts of the pond is used. Fish used in this system include [[catla]] and [[silver carp]] (surface feeders), [[rohu]] (a column feeder), and [[mrigal]] and [[common carp]] (bottom feeders). Other fish also feed on the excreta of the common carp, and this helps contribute to the efficiency of the system which in optimal conditions produces 3000–6000&nbsp;kg of fish per hectare per year.<ref>{{Cite web |title=INTEGRATED LIVESTOCK-FISH PRODUCTION SYSTEMS |url=https://www.fao.org/3/ac155e/AC155E09.htm |access-date=2022-07-11 |website=www.fao.org}}</ref>

One problem with such composite fish culture is that many of these fish breed only during monsoon. Even if fish are collected from the wild, they can be mixed with other species, as well. Thus, a major problem in fish farming is the lack of availability of good-quality stock. To overcome this problem, ways have now been worked out to breed these fish in ponds using hormonal stimulation. This has ensured the supply of pure fish stock in desired quantities.<ref>{{Cite web |title=SEED PRODUCTION |url=https://www.fao.org/3/ac182e/AC182E01.htm |access-date=2022-07-11 |website=www.fao.org}}</ref>