Angelfish are colorful residents of coral reefs. They change their colors and patterns as they grow. Sometimes, the differences between the young and adults are so striking that they look like different species.
Along with their close relatives, the butterflyfish, angelfish are among the most visible inhabitants of tropical coral reefs.Most live in shallow water, and so they are easily spotted by swimmers and divers. This does not mean that all the species occur in large numbers, or in shallow water, however. Some species are not seen on most reef dives because they usually live in deep water. For example, the masked angelfish prefers to live in waters from around 60 feet down to 275 feet.Others are not often seen because they are rare and only found in a few places. For example, the resplendent angelfish only lives around Ascension Island in the southeastern Pacific Ocean.
It is quite normal for a single male to be accompanied by several females.During the breeding season, which usually extends over the summer months, he will breed with each of the females in turn in spawning sessions lasting eight to ten minutes. First, the male will stage a spectacular display some distance off the bottom, in which he stretches out all his fins.One of the females will respond to this invitation by rising to meet him. As she approaches, the male will nuzzle the female’s belly. Following this, the pair will perform a short, high-speed swim during which sperm and eggs are released. As soon as this happens, the pair dash back to the shelter of the reef. The eggs, which float, are carried away by currents and hatch within a day or so.The newly hatched angelfish look nothing like their parents and have spiny scales.
In many species, young angelfish develop body colors and patterns that are totally different from those of adult fish. For many years it was believed that these smaller angelfish were all separate species. It was only through patient observation that it became clear that these strikingly patterned and colored individuals— many of which carry bold white lines on a deep blue body—were the young stages of well-known, but differently colored, species. The behavior of juvenile angels toward adults, and vice-versa, is very interesting. For example, adult angelfish, particularly males, are quite aggressive toward rivals.However, they are considerably more tolerant toward juveniles, acting as if they know that the youngsters do not present a threat. Perhaps they fail to recognize them as members of their own species. The juveniles, for their part, appear to have no respect for the adults, seemingly ignoring the basic rules of angelfish behavior.They swim boldly into the territories of adult males— something that an adult angelfish would avoid, since it means having to face up to the resident male.
In one group of angelfish the adults only grow to a few inches in length, usually under 3–4 inches.These are called pygmy angels. Some of these pygmy angels are especially beautiful, and have names such as the flame back angelfish, the multicolored angelfish, the orange angelfish, the resplendent angelfish, and the lemon peel angelfish. However, the word “pygmy” does not always indicate that a fish is small. Some species, such as the bi color angelfish, the blacktail angelfish, and the Japanese angelfish are all very much bigger.They grow to around 6 inches in length, which is larger than the smallest “non-pygmy” angelfish.They include one called the conspicuous angelfish.