Damselfish are part of the Pomacentridae (anemone fish) family excluding those of the clown fish family Amphiprion and Premnas. They have a single nostril on each side of the head, interrupted lateral lines and two anal spines. There are more than 300 species of damselfish, which are popular in aquariums because of their coloration and general hardiness.
Damselfish vary greatly in size and color from the very drab to the extremely colorful and are lively fish which always on the move. Some such as the blue damselfish (Chrysiptera cyanea) have the ability to change color, especially when frightened they will darken their color and hide. It’s fascinating to see them emerge a vibrant blue and change to deep royal blue, they look like a neon light charging up. Many are highly territorial and defend their area against all comers, large or small. In size, they range from 5 cm (2″) to 30 cm (1′).
Most damsel fish inhabit tropical coral reefs but some live in temperate climates, such as the large orange Garibaldi (Hypsypops rubicundus), which inhabits the coast of southern California and the Pacific Mexican coast. Damselfish are exceptionally tough being hardened in nature by living in coastal rock pools where the temperature and salinity levels can vary greatly.
Damsel fish have a wide ranging diet which include small curstaceans, plankton and algae.
Tips for keeping damselfish in an aquarium: In general it is best not to keep more than one damsel of the same species together due to their territorial nature. Also, depending on the size of the aquarium, it is recommended not to mix too many species of damselfish. Some such as the chromis cyanea and chromis viridis may be kept in groups as they school and are peaceful fish. A small school adds greatly to the attractiveness of an aquarium. The azure camsel (Chrysiptera hemicyanea) meets most of the requirements as an aquarium fish and is a very popular colorful addition to a tank.