5.2.1. The management of rearing ponds

Unit 5 - Fish seed rearing techniques

5.2.1. The management of rearing ponds

The management of rearing ponds is aimed at culturing maximum number of IMC fry to fingerlings within the shortest period of time. The management includes :

(i) removal of weeds by manual/mechanical method
(ii) eradication of predatory and weed fishes by netting and/or poisoning
(iii) manuring with organic and inorganic fertilizers,
(iv) stocking with carp fry in suitable combinations and ratios,
(v) supplementary feeding and
(vi) harvesting.

  • The experiments conducted (during 1965-1967) at Pond Culture Division of CIFRI on rearing of carp fry to fingerling stage in various combinations of IMC and exotic carps, showed average survival of 76.6% (range 53.5 to 97.4%).
  • The species combination consists of catla, rohu, mrigal and common carp; silver carp and grass carp; silver carp, grass carp and common carp.
  • While the rate of stocking varied between 62,500 and 1,25,000 fry/ha, the number of fingerlings harvested ranges between 33,425 and 95,900/ha.
    The production values were in the range of 1,505-3,486 kg/ha (av. 2,204 kg/ha) per 3 months.
  • The CIFRI later conducted 6-month rearing experiments during 1967-1971 and obtained survival rates of 62.1- 98.0% (av. 78.2%) and gross production values 755-2,462 kg (av. 1,712 kg/ha/6 months).
  • In these experiments, fry of grass carp, silver carp and common carp were stocked at 0.1-0.25 million/ha in the ratio of 4:3:3.
  • The survival of silver carp was 99%, while that of grass carp was 80-98%. Zooplankton is the most preferred food of catla fry.
  • The fry of rohu and mrigal accept other feeds, with silk worm pupae resulting in better growth and survival than other feeds such as mustard/groundnut oil cake/rice bran/wheat bran/soybean/prawn waste.
  • A recirculatory system was developed at CIFRI, Barrackpore for carp fry rearing wherein ponds arranged in series were supplied with water passed through a biological filter by means of a pump.
  • Advanced fry of catla (35mm/2.2g) and rohu (45mm/2.9g) recorded high survival of 84.4 and 96.6% and a growth of 90mm (7.0g) and 117mm (14.7g), respectively, in 32 days.
Last modified: Tuesday, 14 June 2011, 10:06 AM