Apogonidae
Apogonidae, commonly known as cardinalfish, are a family of marine fishes in the order Perciformes. They are found in tropical and subtropical waters worldwide. Cardinalfish are known for their distinctive bright red, orange, and yellow coloration, although some species are brown, silver, or black. They are typically small, with most species ranging from 5 to 15 centimeters in length. However, some species can reach lengths of up to 30 centimeters.
Characteristics
Cardinalfish have a compressed, oval-shaped body with a slightly pointed snout. They have a single dorsal fin, which is usually composed of 6 to 12 spines and 9 to 15 soft rays. The anal fin has 2 spines and 7 to 11 soft rays. They have a large mouth with small, bristle-like teeth. Their scales are small and cycloid, meaning they are smooth and rounded. Cardinalfish also possess a distinctive feature called a pseudobranch, which is a small, gill-like structure located behind the gills.
Environments
Cardinalfish are primarily found in coral reefs, rocky reefs, and seagrass beds. They are often found in shallow water, but some species inhabit deeper waters. Cardinalfish are generally nocturnal and hide in crevices or under ledges during the day. At night, they come out to feed on plankton, small crustaceans, and other invertebrates. Some species are known to form schools, particularly during feeding.
Reproduction
Cardinalfish are known for their unique reproductive behavior. Many species exhibit mouthbrooding, where the male holds the eggs in his mouth until they hatch. The eggs are fertilized internally and are typically laid in clusters of several hundred. The male cares for the eggs by keeping them clean and aerated. Some species of cardinalfish are hermaphrodites, meaning they can change sex during their lifetime.
Species
There are over 200 species of cardinalfish, belonging to over 20 genera. Some of the most well-known species include:
- The Banggai cardinalfish (Pterapogon kauderni)
- The flame cardinalfish (Apogon apogon)
- The red cardinalfish (Apogon quadrifasciatus)
- The ocellated cardinalfish (Apogon frenatus)
- The black cardinalfish (Apogon nigripinnis)