This makes it convenient for them to reach their food supply, which consists mainly of flying insects. To an insect that suddenly finds itself the prey of a golden fish charging out of the water, the fish may look more like the tiger its stripes suggest rather than a butterfly. These fish are normally found in pairs, although in captivity, it is suggested that they not be kept in the same tank unless one is much smaller than the other. Some species appear to be monogamous. Courtship is enthusiastic, ending with mating at dusk.
Butterfly fish are egg-layers, and the eggs develop free in the water without parental care.
In many species of butterflyfish, the young are a different color from their parents. The head is armored, with plates projecting from the head toward the back. These larvae grow to a few centimeters across and then transform into a tiny miniature of the adult. Notice its reflection as it hangs near the top of the tank. In captivity it has habituated to its tank, and therefore does not attempt to stay at the top of the water.