Marine Mouthbrooders--Cardinalfish

Cardinalfish Are Some of the Best Saltwater Fish to Breed

Jan 18, 2008

Marine mouthbrooders such as cardinalfish are great aquarium fish for the beginning aquarists, especially if they are interested in trying their hand at captive breeding.

If you entered the saltwater hobby from the world of cichlids, you probably know all about mouthbrooding. If you like mouthbrooders—their interesting behavior and ease of breeding in captivity—then you’ll be pleased to know that some common saltwater species are mouthbrooders as well, including the readily available, relatively inexpensive and very hardy cardinalfish.

Mouthbrooding fish, as the name suggests, carry their fertilized eggs or young in their mouth to protect them from predation when they are most vulnerable. This behavior has evolved given the dangerous environment for any small fish on the reef. Surprising to some, it is the males that care for the brood.

While some reef species are mouthbrooders, most are not. The lack of prevalence for this mechanism of caring for the brood in the reef environment may be the method’s lack of efficiency, given that the number of eggs or young must be limited by the size of the male fish’s mouth.

Of those marine fish that are mouthbrooders, the jawfishes and the cardinalfishes are the best for the beginning aquarist to consider keeping, with the latter being the easiest fish for those who want to try their hand at captive breeding. In addition to being easy to breed in captivity, cardinalfishes are incredibly hardy (read damselfish-hardy).

Cardinalfish are called cardinalfish because many species are, in fact, reddish in color. They are all readily identifiable by way of their large eyes and sometimes bold coloration. Cardinalfish hail from the family Apogonidae—one of the largest family of fishes—and the most commonly available cardinalfish in the hobby are from the genus Apongon and the genus Sphaeramia.

There is little to any sexual dimorphism in many species besides the male being slightly larger than the female in a breeding pair. Either attempt to acquire a known breeding pair or purchase a small group of three and see if two of them pair off. If two of the fish do pair off, you may have to remove the third, as the pair may unrelentingly harass the proverbial third wheel in any tank less than 75-100 gallons (this is more likely with cardinalfish species such as the Banggai Cardinalfish, Pterapogon kauderni, and less likely with a species such as the Threadfin Cardinalfish, Apogon leptacanthus)

Some cardinalfish associate with invertebrates such as sea anemones and urchins. If you are interested in trying to replicate this association in captivity, you may want to consider one of the following pairs of cardinalfishes and invertebrates:

Three Favorite Cardinalfish Species

Additional Resources

The copyright of the article Marine Mouthbrooders--Cardinalfish in Pet Care is owned by Ret Talbot. Permission to republish Marine Mouthbrooders--Cardinalfish in print or online must be granted by the author in writing.