Monday, August 22, 2011

Breeding and Culture of Livebearers (Ornamental Fish)




Livebearers are small ornamental fishes that give birth to live young. The most popular livebearers (guppy, swordtail, platy, and molly) belong to Family Poeciliidae, known as livebearing tooth-carps (upper and lower jaw have teeth)
Livebearers originated from South America. They are considered as beginner’s fish because they are the easiest pet fish to keep and breed. They are not aggressive and can be kept in a community aquarium. They are easy to breed and requires small space and are suitable for small-scale backyard raising.
Creating new color varieties of livebearers is a great challenge to the hobbyist.


Biology
  • Guppy, molly, platy, and swordtail are the most common livebearer species which belong to Family Poeciliidae.
  • Livebearers are omnivores which eat plant and animal based foods.
  • Females (2.5 – 5 inches) are larger than males (1.5 to 3 inches). Males are more colorful than females.
  • Male livebearers has modified anal fin called gonopodium used for depositing sperm into the female.
  • In swordtail, male develop a sword-like tain, an elongated part of the tail.
  • Livebearers give birth to successive batches of live young at an interval of a few days.
Species  – No. of young (fry) – Period b/w mating & birth (days)
  • Guppy – 20 to 200 – 21 to 35
  • Swordtail – 20 to 100 – 28 to 42
  • Platy – 10 to 80 – 28 to 42
  • Molly – 20 to 100 – 40 to 70
During mating, male pursues female by twisting their gonopodium forward and sideways and inserting tip into the vent of the female. Sperm is injected into the ovary through this process.
Embryo develops internally and the young are fully developed at birth (1 cm).
The young readily search for food and could accept artificial feeds.
Sexual Characteristics
Female:
  • less colorful fins and body
  • round body
  • gravid spot
Male:
  • more colorful fins and body
  • well-developed, long fins
  • gonopodium
Breeding Culture Method
A. Materials needed:
  • Breeding tank
  • Breeding cage
  • Rearing/grow-out tank
  • Aerator, basin, pail, scoop net, hose
B. Breeding procedure:
  1. Prepare breeding tank and fill up with water (at least 30 cm)
  2. Select good and sexually matured breeders.
  3. Set breeders in a breeding cage inside the breeding tank.
  4. Stocking density in breeding cage is 100 pcs/sqm. Sex ratio is 1:4 (male:female)
C. Grow-out culture:
  1. Collect fry using a soft and fine-meshed scoop net and transfer to rearing tank. Stocking density is 100 pcs fry/sqm.
  2. Cover the canvass tank to prevent predation by insects, birds, frogs, and cats.
  3. Feed the fry with natural or commercial finfish feeds 3-4 times daily until marketable size.
  4. Change water once a week at 20-33% exchange rate. Siphon fecal matter and uneaten feeds daily.
  5. After 2 months, separate male from female.
  6. Select good quality fishes. Cull out undesirable fishes (dull colored, rotten fins, deformed).
  7. Market size of 5 cm length is attained after 4-5 months. Select good quality and marketable fishes.
  8. Condition marketable fishes in a conditioning tank 3-5 days prior to transport. Provide flow-through water and feed minimally during conditioning period.
  9. Pack the fishes in oxygenated bags. Transport the fishes early in the morning or late in the afternoon.
Disease Treatment
Use commercially available treatment chemicals.
  • For white spot disease/”ich” – 5 drops anti-itch (malachite green)/gal
  • For Anchor worm – 5 drops anti-anchor worm (trichlorfon)/gal
  • For bacterial infection – 5 ppm oxytetracycline or tetracycline HCL
  • For fungus – 5 drops methylene blue/gal
Procedure
  1. Add 1 teaspoon salt/gal water
  2. Permanent (24 hrs) bath
  3. Change water everyday
  4. For 5-7 consecutive days
Note: During treatment, provide vigorous aeration and avoid feeding.
Cost and Returns (25 sqm area, in Php based on 201o prices)
a. Variable Cost – P7,337.00
  • Breeder (160 female, 40 male) – 2,000.00
  • Feeds (breeder and fry) – 388.00
  • Electricity and water – 1,200.00
  • Medicines – 1,000.00
  • Labor – 2,400.00
  • Miscellaneous – 349.00
b. Fixed Cost – P7,402.50
  • Depreciation cost of materials (investment of P23,490) – 5,178.00
  • Repairs and maintenance – 1,000.00
  • Miscellaneous – 1,224.50
c. Gross Revenue – 47,760.00
  • Sales (597 fishes/mo x 8 mos = 4,776 @ P10/pc)
d. Total Cost (A+B) – 14,739.50
e. Net Revenue Profit (C-D) – 33,020.50
f. Return of Investment (ROI)  – 107.1%
g. Payback Period – 0.93 year
For more information, contact:
Ma. Theresa M. Mutia
National Fisheries Biological Center (NFBC)
Butong, Taal, Batangas
Telefax: (043) 421-1465
source:  NFBC

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