Here is yet another almost-perfect marine fish for the beginner to intermediate reefkeeper. It stays relatively small (can even be kept in something as small as a 10 gallon tank, though they do much better in larger tanks), is very peaceful towards other fish, and is relatively hardy. They have these beautiful big eyes and unusual pattern/shape to their bodies, making them very distinctive.
They can be kept singly or in pairs, though sometimes in small groups, they become a little more quarrelsome. With other fish, they are not bothersome at all, and also like to just tread water in the center of the tank, making them the center of attraction a lot of the time. I no longer have a Bangai cardinal, but I do have a related flame cardinal (Apogon sp.) , who is a pretty pink color, but much more shy than the Bangai, prefering to hide in the rockwork except at feeding time.