Finfish Breeding and Hatchery Management

Unit 10 - Breeding of catfishes

10.1.5. Larval rearing

• The hatchlings (5-5.5 mm) reared on Artemia nauplii or sieved zooplankton for 4-7 days, after which they are fed with egg yolk/white suspension for 8-15 days.
• The aerial respiration starts after 10 or 11 days.
• Water exchange 50-60% daily; aged water preferred
• Fingerlings are reared in out-door tanks where they are fed with ground trash fish and rice bran (1:1); stocking density : 200 nos./m²
• Prawn or molluscan meat can also be used
• Attain 6-8 cm in 30 days and are ready for transfer to grow-out pond.

Breeding of Pangasius spp.
• An exotic species now widely farmed in India
• About one lakh tons of fish produced annually
• Fish seed supply is from Bangla Desh and West Bengal

• Pangasius hypothalamus is one of the major fish species in the Mekong River fishery, one of the largest and most important inland fisheries in the world.

•• Originally known as Pangasius sutchii or Pangasius hypophthalmus, this riverine freshwater species is limited to the Mekong River basin in Cambodia, Lao People's Democratic Republic, Thailand and Viet Nam, together with the Ayeyawady basin of Myanmar, within a range of 19 °N to 8 °N. The species has a variety of common English names including Sutchi catfish, iridescent shark-catfish, and striped catfish

•• Like all Pangasiid species, P. hypophthalmus is a highly migratory riverine fish species that makes long-distance migrations over several hundred kilometres (potamodromous) between upstream refuge and spawning habitats and downstream feeding and nursery habitats.

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• P. hypophthalmus is omnivorous, feeding on algae, higher plants, zooplankton, and insects, while larger specimens also take fruit, crustaceans and fish.

•• Mature fish can reach a maximum standard total length of 130 cm and up to 44 kg in weight

•• Females take at least three years to reach sexual maturity in captivity (over 3 kg in weight), while males often mature in their second year, probably taking about the same time in the wild.

•• A female (10 kg) can spawn over one million eggs.

•• Wild broodstock typically spawn twice annually but in cages in Viet Nam have been recorded as spawning a second time 6 to 17 weeks after the first spawning.

Induced breeding
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• P. hypophthalmus can be induced to spawn using HCG or HCG and pituitary gland extract.

•• Females receive 2-4 hormone injections, while males are injected only once at the time of resolving dose to the female.

• • Broodstock are spawned in single pairs or in larger numbers and are usually dry stripped.

•• The eggs are incubated in conical jars made either of stainless steel or glass, with up-welling water flow to keep the eggs in suspension.

•• The eggs hatch within 22-24 hours.

•• Yolk-sac absorption takes takes 24 hours.

•• The larvae are transferred from the hatchery just prior to the complete yolk-sac absorption


Production cycle - illustration

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Nursery rearing

• Nursery rearing is done in 2 separate stages.

•• Earthen ponds (1 000-5 000 m2), are prepared by drying, liming (1 t/ha), manuring and inoculating with Moina.

•• In the first nursing phase larvae are stocked at 400-500/m2 just prior to yolk sac absorption, so that natural feeds are available and the larvae have enough space to avoid cannibalism.

•• Boiled egg yolk and soybean meal mixed into an emulsion is fed 5 -6 times a day for the first 2 weeks. Thereafter commercial pellets are fed.

•• After 4 weeks, the nursery ponds are partially (about 1/3 depth) drained, harvested and stocked at 150-200/m2 in another pre-prepared pond without Moina.

•• Typical larvae to fry survival rate during the first nursing stage is 40-50%.

•In the second nursing stage, from fry to 14-20 g fingerlings, survival over the 2 month nursing period are typically 60-70%.