Catfish hatchery

• Catfishes


  • Widely distributed in many countries in Asia, Africa, Europe as well as Central, South and North America
  • Most catfishes in the Philippines are under the Family Clariidae
  • Have elongated bodies with long dorsal (usually without spines) and anal fins, and four pairs of barbels or "beards" located near the mouth
  • Barbels are highly sensitive taste organs used by catfishes in search for food
  • Have suprabranchial organs which enable them to use atmospheric air
  • Can leave water and walk on land for several hundred meters with their pectoral spines and suprabranchial organs
  • The most studied in fisheries among clariid catfishes are the Asian catfishes Clarias macrocephalus and C. batrachus, and the African catfish C. gariepinus
• African catfish (C. gariepinus)


  • Introduced to the Philippines in the late 1980s
  • A much bigger fish than the native and Thai catfish
  • Has a pointed occipital process
• Native catfish


  • Almost similar in size and appearance to Thai catfish
  • Can be distinguished from Thai catfish by the shape of the occipital process
• Broodstock development and management

  1. Broodstock can be stocked at 10-15 pieces/m2 in earthen ponds or in concrete tanks lined with mud at the bottom

  2. Ponds are maintained at 70-100 cm water level

  3. Catfish are carnivores and feed naturally on insects, shrimps, worms and organic detritus, but easily accept artificial feeds
• Catfish breeding


  • At 3-4 months, sexes can be distinguished externally by the presence of elongated, urogenital papillae in the males, and a round opening in the females at the lower, ventral side of the body
  • When fed properly, catfish mature in about 6-8 months
  • The reproductive organ consists of a pair of ovaries with unfertilized eggs in the females, and a pair of testis found at the anteriormost region
• Catfish contain unfertilized eggs year-round upon reaching maturity, these are not released spontaneously under captive conditions because gonadotropin is not released
• Gonadotropin


  A hormone produced in the pituitary gland that affects reproduction in fishes
• Breeding


  1. The different hormones used are meant to facilitate the release or increase gonadotropin levels in the body of the fish

  2. Luteinizing-hormone releasing hormone (LHRH) is used alone or in combination with dopamine antagonists, e.g., pimozide (PIM) or domperidone (DOM)

  3. Dopamine is found in the brain, which inhibits the release of gonadotropin from the pituitary glands
• Broodstock preparation


  1. Place males and females in separate holding containers

  2. Cover the tanks with nets
• Hormone preparation


  1. For pituitary gland extracts: Get pituitary glands from sexually mature fish, add 1 mL of physiological saline or 0.9% NaCl, macerate using a small vortex mixer, and get the extracts using a glass syringe

  2. For Ovaprim: Dose of Ovaprim is 0.5 µL/g body weight (BW), Injection volume is 1 µL/g BW
• Injection and administration of hormone

  1. Place 5 mL of the anaesthesia (2-phenoxyethanol) in a pail containing 10 liters of tap water and mix well

  2. Place several females at one time into the pail and remove individually the fish that are less actively swimming around with a scoop net

  3. Briefly pat dry the fish with a towel

  4. Get and record the body weight of the fish

  5. Wipe the site to be injected with a cotton moistened with rubbing alcohol

  6. Inject each fish on the dorsal musculature using a disposable tuberculin syringe at 1 µL per g body weight

  7. Put all injected fish in one tank or container and place a net cover
• Testes extraction


  1. Briefly pat dry the fish with a towel

  2. Place each male in the ventral position, and cut up the middle part of the body using a scalpel or scissors

  3. Dissect a pair of testes-seminal vesicles located on both sides of the body and place in a Petri dish

  4. Add 0.9% NaCl or physiological saline into the Petri dish and remove excess blood from the organ with the scapel

  5. Briefly blot dry the organ with tissue paper and transfer to a clean Petri dish

  6. Macerate the organ and add 0.6% NaCl to obtain milt solution

  7. Transfer the milt solution in a small beaker
• Stripping of females


  1. Anaesthetize each gravid female

  2. Dry the body especially the lower ventral abdomen with a towel

  3. Press the abdomen of the female to strip eggs into a clean, dry bowl or basin

  4. Eggs from 4-5 females can be pooled in the same basin or bowl
• Artificial fertilization


  1. Pour the milt solution into the bowl or basin containing the stripped eggs and mix for 30 to 60 seconds using a feather

  2. Add approximately 5 mL of tap water to the bowl and mix further to ensure fertilization

  3. Transfer fertilized eggs to a scoop net and wash with running tap water for about a minute to remove excess milt

  4. Spread the eggs on a monolayer on the net tray inside a flow-through hatching trough
• Incubation of eggs


  1. Use rectangular containers made of marine plywood or plastic basin to incubate eggs

  2. Place fertilized eggs on a framed screen net tray suspended on a slanting position inside the incubation container

  3. Have a flow-through, recirculating water supply during incubation until hatching of the larvae, which is about 24-30 hours when the water temperature is 26-30oC

  4. Use rainwater during incubation to get high fertilization and hatching rates of the eggs
• Hatchery


  1. Observe if most larvae have hatched 24-30 hours after fertilization and incubation

  2. Slowly move the framed screen net tray to drop the newly hatched larvae into the bottom of the trough, leaving only the dead eggs and unhatched larvae on it

  3. Newly hatched (day 0) larvae measure 4-4.5 mm

  4. Larvae can be maintained in a static system
• Larvae management


  1. Clean the hatching troughs by siphoning off dead eggs or larvae, mucus and other foreign bodies at the tank bottom

  2. Change 30% of the water in the trough

  3. Maintain larvae in a static system
• Larval rearing


  1. Feed catfish larvae with newly hatched nauplii of the brine shrimp or Artemia at 10 individuals per mL twice a day

  2. Feed with the cladoceran Moina/Daphnia if available at 5-10 individuals/mL for another 4 days; otherwise, continue feeding Artemia nauplii

  3. Start feeding the larvae with formulated diet in the morning on day 10; give natural food organisms in the afternoon

  4. Siphon dead eggs, larvae or excess feed daily at the tank bottom before replenishing the rearing water and feeding the larvae

  5. Keep the water level at 10-15 cm in depth to allow the larvae to gulp air at the water surface

  6. Provide mild aeration to ensure oxygen supply to the larvae

  7. Change about 30% of the water in the larval rearing tanks daily