Butterflyfish can also swim backwards to escape danger. Many species live as mated pairs and have territories while others school in large numbers. These pugnacious little fish often farm their own patch of algae, aggressively driving away other herbivores. Found almost everywhere on the reef, they also sometimes form large aggregations to feed on plankton. Clownfishes, which live among the stinging tentacles of sea anemones, are also members of this family.
Movement is slow except when attacking prey with remarkable speed.
All groupers are carnivorous, feeding on invertebrates and other fish. Like wrasse and parrotfish, some start out as females and become males later while others are hermaphroditic. They have large protruding eyes which are raised above the level of the head and powerful jaws which enable them to snatch prey and dart back to safety. Gobies are among the most successful reef families, with literally hundreds of species. In fact new species of these small, secretive fish are being discovered all the time.