Spawning starts when the female swims over the cleared patch of rock and deposits a small line of eggs with her ovopositor. The males follows shortly after and fertilizes them. The process of laying eggs takes anywhere from 2 to 3 hours. The eggs look like little capsules about 2 to 3 mm long and 1 mm wide. If the adults have been fed well the eggs should be a bright orange color. During this time the clownfish, notably Amphiprion clarkii, may lay up to 600 eggs. More often than not however, the number of eggs start out small, around 200, and increases with each spawn and as the female increases in size. Once the fish have started spawning they're likely to repeat it at intervals of around 12 to 18 days.
The eggs usually take from 6 to 15 days to hatch depending on the temperature. One day before hatching the larvae develop a silvery color around their eyes. This is the time when you must make a decision: Either you leave the eggs in the tank to hatch, and you remove the larvae, or, one day prior to hatching you remove the live rock upon which the eggs were laid.