Small fishes rule the marine aquarium world. If you only have space or cash for a small tank, they’re a godsend. Have a huge tank? Well, even then, they’re awesome because you can keep many more small fish than big fish. Okay, sure, there are some awesome big fishes–pomacanthid angelfish, for example. Nothing against those at all, and you can in fact get one or two bigger species as show specimens. But still–the small fishes rule. And among them, none have enjoyed such enduring popularity as the damselfishes. Small in size, but with big personalities, damsels not only add lots of activity to a tank but also plenty of bright (very often bright blue) color. One of the most desirable, and indeed blueist, of damsels is the azure damselfish.
Azure damselfish natural history
Both the common and scientific name of the azure damsel (Chrysiptera hemicyanea), also known as the azure demoiselle or half blue damselfish, refer to its unusually bright blue pigmentation. An intense, metallic blue covers its upper body and most of its flanks. An equally bright and beautifully contrasting yellow color covers the belly, anal fin and base of the tail. Many species in its genus share the same basic color pattern, with the only difference being different amounts of yellow. However, as a rule of thumb, male azure damsels have more yellow coloring than do females or juveniles.
The azure damselfish is native to the eastern Indian Ocean and West Pacific Ocean. The species is most abundant within the Coral Triangle (the Solomon Islands to Indonesia, Bali and the Philippines). It is found off the eastern Sulawesi and Kai Islands In Indonesia and off the North-West shelf of Australia at Scott Reef, Ashmore Reef and the Rowley Shoals. Interestingly, it has recently been observed in the central Mediterranean Sea near Sicily and Malta.
Most often, adults are seen near shallow (1-38m deep), sheltered shores and lagoons. Pairs or groups of juveniles and subadults are often seen around near-shore branching coral colonies (especially Acropora). It is a diurnal species, being most active during the day. Much of its activity is devoted to hunting zooplankton and small benthic invertebrates such as copepods. It is rather nervous, quickly dashing into the coral branches with the approach of any larger, potentially predatory fish.
The azure damselfish is an oviparous species that forms distinct pairs while breeding. The demersal eggs stick to the rocky substrate. After breeding, the male guards and aerates the eggs until they hatch. There is no pelagic larval stage. Instead, the very young individuals (which develop quickly) hang around under the protection of their father. The species is quite prolific, with a doubling time of only 15 months. In the wild, its life span is said to be anywhere from 2-6 years (though some suggest it can survive as long as 15 years in captivity); it reaches a length of 3 inches (8 centimeters).
Because of its stunning beauty and ease of care, the azure damselfish is (much like the closely related Chrysiptera talboti and C. rollandi) widely utilized. Because of its ability to withstand suboptimal water chemistry and disease, it has been highly recommended for beginner aquarists. While not as brutal as some other damselfish, it certainly can have a mean streak. While it technically is a schooling fish, it’s fairly aggressive and territorial, including (and perhaps especially) towards its own kind. For this reason, it’s best to acquire only a single specimen. The only way to keep multiple specimens is to add them to a large tank with many rocky hiding spots; but even then, a relentless aggressor may pummel an unlucky competitor to death. Pairs may be acquired, but there’s no telling if ‘divorce’ and maybe even murder is on the horizon. Its aggressiveness is somewhat reconciled by the fact that it is quite reef-safe.
Like its damsel brethren, the azure damsel is very easy to feed. Any sort of plankton-like food will do. They even accept flakes, pellets, and similar prepared diets. Of course, a higher quality diet will mean the brightest possible coloration. Also, offerings of live food such as live brine shrimp (even if just as an occasional treat) provide the opportunity to observe the species awesome hunting ability–you’ll be surprised at the lightning speed with which it can snatch baby brine shrimp from the water column.
While wild specimens are easily available in the trade, the recent availability of a farmed alternative from ORA is exciting. These tank bred individuals may be more social, are less likely to introduce a disease to their new system and are even more hardy.
Given its hardiness, its spunk and especially its flashy blue coloration, every reef tank should house one of these beauties. In fact, now that the azure damselfish is farmed–and is thus even more sustainable–it is downright impossible to resist. We certainly hope that ORA and other hatcheries continue to work with more and more damselfish species; as kings of the small marine aquarium fishes, every new species offers new opportunities to introduce a dash of colorful fun to your reef.