Butterfly Fish

Another popular saltwater aquarium fish is the butterfly fish. It is a member of the Chaetodontidae family. Banner fish and coral fish are also included in this group, which can be found among the tropical reefs in Atlantic, Pacific, and Indian oceans.

Butterfly fish look like smaller versions of angelfish, but differ in that they do not have spines at the gill covers. Most of them have brightly colored and uniquely patterned bodies, featuring hues of yellow, red, orange, blue, white and black. This beautiful coloration make the butterfly fish a popular saltwater aquarium fish.

The butterfly fish got its name because of the “eye spots” many display on their flanks, which resemble those on butterfly wings. By night, butterfly fish display a different coloration and hide in reef crevices and caves. Their bodies are flat, with long dorsal fins and tail fins that may be round or short. They are also distinguished by rows of brush-like teeth found in their small, protruding mouths.

They are relatively small fish. In the wild most are from 7 to 9 inches in length, however as with most fish confined to saltwater tanks, their size in confinement will depend on their immediate environment and are  much smaller in a typical aquarium setup.

Most butterfly fish species feed on coral polyps and sea anemones, which can interfere with the delicate balance in reef tanks. The favored species for aquarists are the zooplankton feeders, and these can be added in to tanks in groups, with the number of fish depending on the size of the tank.