2. • After stocking- attain a length of 20-25mm in 15
• Artificial feeding-less than 10 % to as high as 95-100%
• The rearing ponds - second phase of carp culture
• fry to fingerlings- rearing ponds
• The rearing period - 2 and 3 months
Figure: A series of rearing ponds Figure: A haul of carp fingerlings from a rearing pond
3. 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
(vi) Harvesting
4. • The experiments conducted by CIFRI in various combinations of IMC and exotic carps,
showed average survival of 76.6% (range 53.5 to 97.4%)
• The species combination -catla, rohu, mrigal and common carp; silver carp and grass carp;
silver carp, grass carp and common carp
• Rate of stocking - 62,500 and 1,25,000 fry/ha, the number of fingerlings harvested ranges
between 33,425 and 95,900/ha
• The production value- 1,505-3,486 kg/ha (av. 2,204 kg/ha) per 3 months.
5. • The CIFRI – after 6-month rearing - 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)
• Here, 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 - silver carp -99%, grass carp - 80-98%
• Zooplankton - most preferred food of catla fry
• The fry of rohu and mrigal accept other feeds, with silk worm pupae mustard/groundnut
oil cake/rice bran/wheat bran/soybean/prawn waste
• 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
6. Rearing carp seed in pens/cages
• cage and pen systems
• For rearing larvae, fry and fingerlings
• Cages and pens - abundant supply of oxygen, flushing of metabolic wastes of the
stocked fish, and nutrients from the catchment area
• In India, rearing of major carp seed in pens - Bhavanisagar and the Tungabhadra
reservoirs
7. Rearing of carp seed in pens erected in the Tungabhadra reservoir
• Rearing of larvae in pens in Tungabhadra Board - one of the best managed and largest
fish seed farms in south India
• The main objective -nurse the delicate carp spawn in pens up to fingerling stage and
then stock them in the same reservoir in order to improve the fish landings and boost
the socio-economic status of fisher folk
• It produced 24 t in 1954-55 and 4,200 t in 1981-82 : mainly catfishes, minor carps,
minnows, etc.
8. • An ideal site for pen erection - gentle slope with red loamy soil where water remains for
a period of 2-3 months between August and November
• protected from wind and wave action
• A pen is normally made up of casuarinas poles, 2 m high, fixed at intervals of about 1.2
m, enclosing an area of 2,000 to 5,000 m2
• Between the vertical poles, three horizontal rows of spilt bamboo stripes are tied to give
support for the net materials
9. • Close mesh (monofilament nylon fabric, 30 mesh) having a width of 1.5 m is used as the
pen wall material
• The bottom of the nylon fabric is inserted firmly into the mud and the vertical part
securely tied to the poles and bamboo stripes
• After establishment of pen, the enclosure is limed, fertilized with cattle dung and
treated with soap-oil emulsion
• The water in the pen is about 1.0-1.2m deep.
10. • The pen - stocked with three-day-old major carp larvae (4-5 million/ha), fed with a
mixture of groundnut oil cake and rice bran at a ratio of 1:1, from a boat
• Pens are periodically manured with organic and inorganic fertilizers to sustain
production of zooplankton
• 10,000 kg cow dung, 400kg urea and 100 kg superphosphate per ha, followed by
repeated applications, at 10% of these rates, every two or four weeks
11. • Survival to 70-80 mm fingerlings is as high as 60% after three to four months
• Fishing licenses are given to local residents to uplift their socio-economic status
• Advantages of pen:easy, easy, less expensive and efficient for the nursery rearing of carp
fry
• Drawback: the shortage of foreshore area for large-scale pen operation.
