Cardinalfishes belong to the family Apogogonidae, which contains several genera and over 200 species.
One of the most common cardinalfishes found in the home aquarium is the Banggai Cardinalfish (Pterapogon kauderni). They are good saltwater fish for beginners due to their hardy nature.
Banggai cardinalfish get their name because they are found in the waters off the cost of the Banggai Archipelago Islands on the eastern end of Indonesia. They are usually found in shallow waters and often hide from their predators among sea urchins and sea anemones (similar to clownfish).
Cardinalfish don't grow very large and the Banggai cardinalfish only reaches an adult size of about 3-4 inches (8-10 cm). They are good fish for reef tanks and they are peaceful fish that shouldn't be kept with agressive species or fin nippers. You should keep a group of about 6 Benggai cardinalfish together providing you have room in your tank. Be sure to provide plenty of rockwork for hiding places.
Cardinalfish are carnivores. They will eat meaty frozen or live foods as well as vitamin enriched brine shrimp. You can also feed them finely chopped shrimp or squid.
They have a life span of about 5 years. You can tell the juveniles from the adults because adult fish have spots on their fins, but juveniles don't.
Males and females are similar in coloration, however, when cardinalfish are in breeding condition the jaws of the male fish turn darker and the female's body will be more round due to the eggs she is carrying.
They will spawn in captivity. If you have a group of cardinalfish in your aquarium they will pair themselves off. Once they do, put the pair in their own breeding tank. You should have plenty of rockwork for hiding places in the tank.
All cardinalfish are mouthbrooders. For Benggai cardinalfish, it is the male fish that keeps the eggs and fry in his mouth until are fully developed. He will carry them in his mouth for about 20-30 days. During this time he will not eat.
After he stops keeping the fry in his mouth he should be removed from the tank or he may eat them (which is why hiding places are very important in the tank). As with all small fry, watch the method of filtration you use in the tank or the fry may get sucked into the filter. A sponge filter is best for fry tanks.
As soon as the fry are freeswimming feed them newly hatched brine shrimp.
Banggai cardinalfish can be purchased for about $20-25 each.