Common names : English - catla; Hindi-bhakur, catla; Bengali-katal; Punjabi-theila; Burmese - nga-thaing

History of use: Catla is distributed the rivers of the Indo-Gangetic system in Bangladesh, India and Pakistan and in the rivers of Myanmar that drain into the Bay of Bengal. It is a very popular food fish. It was introduced between 1904 and 1921 from the river Godavari to the canals, rivers and reservoirs of southern India and during 1930's and 40's to Maharashtra (Powai Lake, Mumbai) and to Kerala (Periyar Lake). It has also been introduced to other countries, including Japan, the Philippines and the former USSR (Jhingran 1982).

Production Statistics : There are no reliable statistics on production of catla from aquaculture.

Where farmed : Region - South and Southeast Asia, FAO Area - 04, Asia, Inland.

Countries: Bangladesh, Cambodia, India, Laos, Malaysia, Maurituis, Myanmar, Nepal, Pakistan, Sri Lanka and Vietnam.

Climate and environmental tolerance : Tropics; hardy; natural temperature range 18-300C; lower and upper thermal tolerance limits, 16.7°C and 39.5°C; sensitive to low oxygen conditions; tolerates pH 6.5-8.5 and salinity up to 5 ppt; prefers deep pools; breeds during the southwest monsoon (May - September) in water temperatures around 24 - 31°C.

Current farming methods: Catla breeds naturally in flooded fields and can also be bred by simulating riverine conditions in special ponds called dry bundhs. Catla is now mostly spawned artificially in hatcheries. It is more difficult to spawn than most other carps, and requires good broodstock management. This is sometimes lacking on farms. The postlarvae called renu, dhani or jeera in Bengali and are also commonly called 'spawn' in English. Catla attain first maturity when about two years old and 442 mm length (Natarajan and Jhingran, 1963). In nature, they spawn only once during the breeding season but have been spawned up to four times in hatcheries (Gupta et al. 1995). Fecundity depends on the age, length and weight of the fish and the weight of the ovaries and varies from 0.2 to 4.2 million n fishes weighing between 11.3 to 18.4 Kg fish. The number of eggs/kg body weight of fish from well-managed broodstock is about 100,000.

For induced spawning, two injections of crude carp pituitary gland (2-3 mg and 5-8 mg/kg) are given to a female at an interval of 4-6 hrs, as against only one (2-3 mg/kg) to males at the time of the second injection to females. A female and two males in a running water spawning task should then spawn within six hours. If spawning has not taken place, the female is stripped and the eggs fertilized with semen stripped from males. The fertilized eggs hatch after 18-24 hrs, depending upon the water temperature. Optimum temperature for spawning and hatching is 280C (Chaudhuri 1963). Jhingran and Pullin (1988) have reviewed the use of materials other than carp pituitary, for induced spawning. The yolk-sac is absorbed after three days.

The postlarvae are easy to handle and cheap to transport, packed in plastic bags with oxygen. The postlarvae feed exclusively on zooplankton - rotifers and small cladocerans. Nursery ponds (about 400 m2, 1m deep) are prepared by liming and fertilization with cow manure or poultry litter. Prior to stocking, large copepods and various insects (especially notonectids) and their larvae are predators on the postlarvae and are eradicated from the nursery ponds with appropriate chemicals (Jhingran and Pullin 1988). The postlarvae are given supplementary feed (a fine powder comprising a 50:50 mixture of groundnut or mustard oil cake and rice or wheat bran) daily at two, three and four times the weight of postlarvae stocked, increasing the amount at five-day intervals. Stocked at 5 million/ha, postlarvae have a survival of 60 - 70%. The fry are then transferred to rearing ponds (800 - 1200m2, 1.5m deep) for raising to fingerlings for stocking in growout ponds or other waters.

Growout ponds (0.2 - 5.0 ha) are limed and fertilized before stocking with carp fingerlings at 5,000-10,000/ha. The proportion of catla in the stocked population is 10-35% depending upon the species mix used for polyculture. In polyculture of Indian major carps alone, the proportion of catla can be 30-35%, but in polyculture with exotic carps, the proportion of catla is reduced to 10%, with silver carp (Hypophthalmichthys molitrix) constituting 20% of the total population. The ponds are fertilized every two weeks with cow manure, or a combination of inorganic fertilizers.

Supplementary feed, comprising a 50:50 mixture of oil cake : cereal bran is provided daily at 2-3% body weight based on the growth registered every month. Its contribution to total production ranges from 10-30%. Monoculture of catla is not practiced.

Processing and marketing: Some reservoirs in India produce large-sized catla (35-40 kg in weight) which have a special market during the marriage season. Catla has a large sized head, but is otherwise highly suitable for filleting.

Likely future trends: Catla is a very important species for aquaculture. Seed production currently falls far short of demand. If the availability of catla seed increases and if growth rates can be further improved through genetic enhancement, the contribution of catla to aquaculture production in the Indian subcontinent will increase, with a decline in the importance of silver carp in carp polyculture systems. Catla also has good potential for processing into fillets and other valued-added products for export.

Intergeneric hybrids of catla with Indian and other carp species have been produced (Tripathi 1992) of which the rohu female x catla male hybrid combines the advantages of the deep body of the catla and the small head rohu. This hybrid is fertile. Naturally occurring catla x rohu hybrids have been found in the Rihand reservoir.

References :

Chaudhuri, H. 1963. Induced spawning of Indian carps. Proc. Nat. Inst. Sci. India (B), 29(4) :478-87.

Gupta, S.D., S.C. Rath, S. Dasgupta and S.D. Tripathi. 1995. A first report on quadruple spawning of Catla catla (Ham.). Vet. arichiv 65, 143 - 148.

Jhingran, V.G. 1968. Synopsis of biological data on catla, Catla catla (Hamilton, 1822). FAO Fish. Synop. (32) Rev.1: pag.var.

Jhingran, V.G. and R.S.V. Pullin. 1988. A hatchery manual for the common, Chinese and Indian major carps. ICLARM Studies and Reviews 11. Asian Development Bank and ICLARM, Manila, Philippines, 191 p.

Jhingran, V.G. 1982. Fish and Fisheries of India. Hindustan Publishing Corporation (India), Delhi. 666p

Tripathi, S.D. 1992. Three decades of research on carp hybridisation in India, p 00 - 00, In Symposium on Zoological Research in Relation to Man and Environment, 1- 4 March, 1992, Zoological Society, Calcutta, India.

S.D. Tripathi