Clownfish breeding begins with obtaining a pair of mated individuals. The couple can be ordered from a local pet store, or a pair of very young Clownfish can be purchased. Clownfish are all males when they are young. As they grow, the most dominant fish in a pair changes to female. This sex change can take anywhere from 6 to 8 months.
It is important that the Clownfish couple are housed in a tank that holds no less than 30 gallons. This gives the fish enough space to conduct their mating rituals and egg laying. Other fish can be kept in the tank during the Clownfish breeding process; however, these other fish should be docile and not aggressive, as aggressive fish may stress the Clownfish and result in poor quality eggs, or none at all. Cleaning the water regularly also helps facilitate a healthy breeding cycle. Once the cycle has begun, the female Clownfish begins to look slightly larger as she becomes pregnant with eggs. The fish couple prepares a place to lay the eggs, usually on a flat surface, such as a rock or the bottom of the tank. Once the area is clean, the female swims over the top of the surface and begins laying the eggs. The male then swims along behind and fertilizes them. This process may take up to an hour. The male then cares for the eggs until they hatch.