Flowerhorn cichlids are ornamental aquarium fish noted for their vivid colors and the distinctively shaped heads for which they are named. Their head protuberance is formally called a nuchal hump. Like blood parrot cichlids, they are hybrids that exist in the wild only because of their release. Flowerhorns first emerged for sale on the aquarium market in Malaysia in the late 1990s and soon became popular in many countries in Asia. They are commonly kept by hobbyists in the US, Asia, and Europe. Numerous cast-off flowerhorns have been released to the wild, especially in Singapore and Malaysia, where they have become an invasive pest animal. Their importation is banned in Australia.
