Apogon maculatus is a cardinalfish from the western Atlantic. Apogon maculatus is a nocturnal fish, and it usually hides in shadowy areas. This fish can be viewed with a red light in a dark room if needed to. It occasionally makes its way into the aquarium trade because of its uniqueness. In captivity the fish's color tends to fade unless fed color enhancing vitamins. It grows to a size of 11 centimetres (4.3 in) in length. This fish can be aggressive towards other cardinal fish. Only one should be kept in a tank unless in mated pairs, or two can be placed in a 55 imperial gallons (250 L) or larger tank. Otherwise it does well with peaceful tank mates as long as it has caves and places to hide. The ideal water conditions are temperatures of 72–78 °F (22–26 °C), with a pH of 8.1 to 8.4, sg