Cardinals are popular as they are easy to care for and stay relatively small.  They do well in a coral reef or rock reef environment.  Cardinals are commonly seen in large groups which protects them as they give the illusion of one big fish.  They are very docile and friendly, making them a great community fish.  Cardinals will eat most prepared foods as well as meaty seafoods.  They are easily a favorite as they dominate the top waters and tend to stay out in the open.