At the time of writing this section, the cardinalfish family includes around 350 described species.
Unfortunately, not all cardinalfish are sold, so this encyclopedia can only give an overview of animals that have been sold so far.
Cardinalfish are usually smaller than other groupers. Their range extends from the Indo-Pacific to the Caribbean.
The largest cardinalfish (Cheilodipterus macrodon) reaches 24 cm, while the smallest (Apogonichthys ocellatus) only 4 cm.
However, they are mostly small, peaceful and generally nocturnal fish. They got their name because the main coloring of many of these fish is red. They are planktonic carnivores, generally with large eyes and mouths, some of which are very colorful. In the majority of cardinalfish, delicate longitudinal stripes predominate on the body. All carry a clearly divided dorsal fin. The head, mouth and eyes are very large. Despite their large eyes, they rarely live at very great depths, but mainly from the water surface down to around 50 meters. A few species can also cope with lower temperatures, sometimes even below 20 °C.
Most species of this genus stay among coral branches during the day and search for food at night. They find refuge in the coral stocks, but unlike others, they feed on coral polyps.
Cardinalfish are pure plankton hunters, but generally do well in the aquarium with substitute food.
As already mentioned, they are active at dusk and at night. Even when everyone is asleep, they are still on the move and alert.
They are mouth brooders, with the males incubating the eggs. That would be a chance for offspring in the aquarium.
Cardinalfish are best kept in small groups and should have adequate dens and hiding spots with dim lighting.
Contrary to a widespread assumption, they are not schooling fish, with the exception of the Zoramia leptacanthus.
