Different systems of polyculture of fishes are traditionally practiced in India to utilize various types of inland water resources available in the country. The usually cultivated species of fish in freshwater polyculture are Catla catla, Labeo rohita, and Cirrhinus mrigala. Culture of Chinese carps along with major Indian carps has recently been developed in India as composite fish culture, and with this, production as high as 3000–5800 kg/ha per 6 mo and 7000–9000 kg/ha per yr has been obtained in still-water ponds in different parts of the country. The magnitude of production is significant considering its application to the large resource of ponds and tanks totaling about 1.6 million ha, thoughonly 1 million ha are presently available for carp culture. The remaining 0.6 million ha comprise swamps and derelict waters. The cost of swamp reclamation being high, techniques of mixed culture of air-breathing fishes are being developed to utilize these water bodies as such and already a production of 895 kg/ha per yr of murrels has been attained without any fertilization and supplementary feeding. Further, to utilize about 2.0 million ha of culturable brackish waters available in India, research investigations are well underway to manipulate the tidal impoundments for mixed culture of brackish water fish and prawns with proper scientific management.
Hemato-biochemical and Genetic Damage Caused by Triazophos in Fresh Water Fish, Labeo rohita