Marine Angelfish: Color and Style.

By Jay Hemdal.

Fish from the Pomacanthidae family, the marine angelfish, are probably the most popular species of saltwater fish kept by marine aquarists. The fantastic colors and relatively hardy nature of these fish make them extremely desirable. There are approximately 80 species of angelfish, all from tropical seas (typically between the latitudes 30 degrees north and south of the equator).

The primary habitat of these fish is the coral reefs, where they can be found down to depths of about 650 feet, although some species are found in sea grass areas as juveniles.

Breeding marine angelfish in captivity has eluded hobbyists. Some species of pygmy angels have been reported to spawn in small marine aquariums, but no fry have been raised. In nature, angelfish are egg scatterers.

There are certain facts about marine angelfish that must be understood before an aquarist should even consider adding them to a saltwater aquarium. First and foremost, although marine angelfish are considered relatively hardy, particularly in relation to other species of marine fish, they should not be exposed to the physical stresses of a newly established marine tank. The aquarium should be set up and running for three or four months before adding any species of angelfish. This ensures that the nitrogen cycle in the tank has been completed and the levels of ammonia and nitrite are so low as to be immeasurable.

Angelfish typically exhibit significant intraspecific aggression. This means that they seldom tolerate the presence of others of their own kind in the small enclosed space of a home aquarium. They also can be aggressive toward other species of angelfish of similar size and shape. If an aquarist wishes to maintain more than one angelfish in a tank, it is best to build the population slowly, starting with a small angelfish. This gives the smaller fish an opportunity to create a territory it can defend before another angelfish is introduced.

Acclimating Angelfish is very important, as these fish have been known to go into shock.

Turn off all the tank lights (greatly reduces aggression) and rearrange some key rocks gently (putting them on equal-ground for space). Make a smooth transfer of the fish. Monitor it constantly (even though it will be hard with the lights off). Turn on the lights 24 hours later. This will be the main aggression display. If there are problems, turn lights off for another 24 hours. Angelfish are not aggressive, however, with species from other families, such as clownfish, wrasses and so on.

It is also important to know the care requirements of the species you are interested in. Find out what foods will be accepted, how large the fish will grow and the general hardiness of the species. Avoid very small specimens (less than 1 inch) — they must feed continuously to avoid starvation. Conversely, avoid very large specimens — they ship poorly and are much less likely to adapt to captivity, both in terms of available space and the foods likely to be offered by an aquarist.

It is very important to carefully choose the species of angelfish you are going to buy. Not all species adapt equally well to captivity. You should also be aware that many species of angelfish change color as they mature.