Blue Devil Fish Facts

The largest blue devil fish measured was 3.3 inches, but adults tend to average closer to 2.5 inches. As suggested by its name, most of the body is blue. Juvenile and female blue devils have a black spot near their tails but are otherwise blue. Males have more decorative coloring, with bright yellow snouts and tails. When the fish are scared, they will hide in nearby rubble or caves and turn almost completely black until the threat is gone.

Blue devil fish are naturally found in the western Pacific and eastern Indian oceans, with the majority of their habitat around Indonesia and the Philippines. They are associated with the warm waters of reefs. Their ideal temperature is 74 to 78 degrees. They're found from the surface to depths of 33 feet. Blue devils prefer the rubble and natural caves of coral, where they take shelter.

Blue devils are omnivores; they will eat just about anything, which makes them easy fish to feed in home aquariums. Feed flake or pellet fish food as a diet base, and supplement with vegetables and fresh or frozen meaty food to provide a balanced diet. Blue devils will feed on algae and other naturally arising foods. Be careful not to stick your hand into a tank with blue devils, because they are known to bite, especially when anticipating food.

Blue devils are mellow fish when they are juveniles, but as they get older they become territorial. Set up your aquarium so they can claim just a section of it; otherwise they will chase off other fish. Also, if you are going to have multiple blue devils, have one male with several females and introduce them all to the tank at the same time.