Marine Angelfish are found on shallow reefs in the tropical Atlantic, Indian, and mostly western Pacific oceans. The family contains approximatley 86 species and they should not be confused with freshwater angelfish or the tropical cichlids of the Amazon River. With their vibrant colors, marine angelfishes are some of the more conspicuous residents of the reef and closely resemble their relative, the butterfly fish. They are distinguished from the butterfly fish by the presence of preopercle spines (part of the gill covers) from which their name is derived; Pomacanthidae from the Greek poma meaning “cover” and akantha meaning “thorn.” The larger species are also quite bold and known to approach divers. Most angelfish restrict themselves to the shallows of the reef, seldom venturing deeper than 50 meters. They are diurnal animals, hiding amongst the nooks and crevices of the reef by night. Some species are solitary and form mated pairs while others from harems with a single dominant male over several females.
Butterflyfish, while similar in looks to the angelfish, tend to be much smaller in size and range from 12 to 22cm in length. Their bodies have striking patterns with shades of black, white, blue, red, orange, and yellow. Many have eyespots on their flanks and dark bands across their eyes, not unlike the patterns seen on butterfly wings. Generally diurnal, butterfly fish inhabit water of less than 18 meters and often stick to particular home ranges. The corallivores are especially territorial, forming mated pairs and staking a claim to a particular coral head.