Mature broodstock P. hypophthalmus are induced to spawn in hatcheries using HCG or HCG and pituitary gland extract. Female broodstock are given between 2-4 hormone injections while males are injected only once when the female resolving dose is given
Broodstock are spawned in single pairs or in larger numbers and are usually dry stripped. The eggs are incubated in conical shaped jars made either of stainless steel or glass, with up-welling water flow to keep the eggs in suspension
Depending on water temperature, the eggs hatch usually hatch within 22-24 hours. Yolk sac absorption takes a further 24 hours. The larvae are transferred from the hatchery just prior to full yolk sac absorption