The Asian Arowana is a difficult fish to breed, even harder under glass tank or fibre glass pond conditions. It will only breed in natural earth ponds when they reach maturity between ages 3-5. Asian arowana are hard to sex, especially when they are young. Generally, males are larger in size and fins then its females siblings which give them a more errogant look. They also have a wider and deeper jaw(to hold the eggs and fries). Femles, on the other hand are smaller in size and has more rounded body. It takes alot of experience to sex mature asian arowana. Only when they stared breeding, then you can be 100% sure which one is male and which is female.
When a pair is formed, the male will swim closely to the female and will chase the rest away. The pair will start to develop their territory.
The courting will take 1-2 months, during this period, they will swim closely together(often in circular motion), chase and bites each other's tails and fins and often cause injuries to each other. Thier appetite will drop gradually as the pair come near to the time ready to spawn. The abdomen of the female will start to swell up and fill with eggs. They will then choose an area for egg laying, usually a less distrubed area with weak current. They will swim parallel to each other, rubbing against each other and occasionally stay motionless. Eventually, the pair will stop swimming and continue body rubbing action. With a sudden spawn (usually late afternoon), the female release her eggs and simultaneuosly the male reeases his sperm to fertilize them. The number of eggs laid between 30-80, each measured around 12-15mm in diameter. The eggs are orange-red in colour and are very fragile. When the eggs are fertilized the male immediately scoops up as many eggs as possible. The remainder are usually eaten up by the female to regain nutrients.
The male will incubated the eggs in his mouth for about 50-60 days until they hatch. For the first few weeks, the fries will leve in the father's mouth and will take nutrients from their yorsac. The fries will start to leave the father's mouth when they reach to sizes of 4-5cm. At this stage, the fries start to leave the father's mouth.The fries can be removed from the parent if they accept the food well for at least few days. You may start to feed baby arowana blood worms or baby guppies.