Yellowtail Damselfish

The Yellowtail Damselfish is extremely hardy and gorgeously colored. In fact, Chrysiptera parasema is considered by many aquarists, both beginning and advanced, to be the ultimate damselfish. This is partly because its jewel-blue body is contrasted by an energizing yellow tail. This color combination looks stunning against any backdrop of corals and live rock. But what pleases aquarists most is that the Yellowtail Damsel is less aggressive and does not need as large of an aquarium as other Damsels. It can be housed with a variety of tank mates but because damsels become more aggressive as they mature, smaller or very weak fish are not recommended. Fish types that could be at risk include small juveniles of butterflyfish and Centropyge angelfish, cardinalfish, etc. A group of several individuals of this species can be kept together but only if there are many hiding places, otherwise they may very well fight to death. Some good tank mates include other non-aggressive damselfish, (but not of this genera), larger butterflyfish, and wrasses. Very territorial dottybacks, and such fish as sea basses that will eat anything, are not recommended if the tank is not large enough. In addition The Yellow Tail Damsel is a very hardy fish and quite territorial. Many people will use this fish to cycle a new tank, although Reeftime.com does not endorse this practice. Not only does this place undue stress on the fish, but it also sets up a precarious situation for any new inhabitants of the tank. Damsels are so aggressive that once they have their territory staked out, they will likely kill any new additions to the tank.

After establishing a territory, a male damselfish cleans a rocky ledge or coral surface to prepare it for spawning. Using color changes, excited swimming movements, and, in certain species, clicking sounds, the male fish encourages a mature female to approach the spawning site and lay her eggs, which he quickly fertilizes. Courtship and mating take about 10 to 20 minutes. Some males may mate with several females. Each female fish lays up to 20,000 tiny oval eggs, which the male tirelessly guards and tends. He fans water across the eggs with his fins, sometimes picking out dead eggs that could threaten the whole batch. Male damselfish defend their eggs against fish much larger than themselves with little regard for their own safety. The eggs hatch after three to seven days, and the larvae spend weeks drifting and feeding on animal and plant plankton. Some species of damselfish mature at two or three years of age while others take much longer. During courtship rituals vibrant colors distinguish the sexes more clearly.


Native to the reefs of the Indo-Pacific, this member of the Pomacentridae family prefers multiple hiding places and peaceful tankmates. Though most Yellowtail Damselfish will ignore other fish, invertebrates, or corals, some may be territorial towards its own kind or similar-sized fish. The Yellowtail Damsel is best kept in small groups of odd numbered fish in suitably sized systems.

Yellowtail Blue Damselfish or Yellowtail Demoiselle, and sometimes confused with the Azure Damselfish, C. parasema feeds on zooplankton and algae in the aquarium. For best care, it should also be fed a varied diet of meaty foods, such as mysis and vitamin-enriched shrimp. It is best to feed several small meals throughout the day.

Yellowtail Damsels have been bred in captivity. Though difficult to sex, males are usually larger and more slender and become aggressive towards females when ready to mate. However, the male Yellowtail Damsel is ultimately responsible for the care and guardianship of the eggs and will become very territorial while watching over his brood. But it is difficult to identify the sex organ of this fish.