These beautiful fish, with their minute, brushlike teeth, browse on sponges, algae and corals. Their vibrant coloring varies according to the species, like those of the butterflyfish and were once thought part of the same family. However, they are distinguishable by a short spike extending from the gill cover. Angelfish are territorial in habit and tend to occupy the same caves or ledges for a period of time. 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.