Chrysiptera parasema, from the Greek words "chrysos" meaning golden and "pteron" meaning fin/wing, is a species of damselfish commonly referred to as yellowtail blue damselfish or yellowtail demoiselle. The gorgeous yellowtail blue damselfish has a vibrant sapphire blue body with a bright, yellow tail. The males tend to be larger than the females. The yellowtail blue damselfish is often confused with a close relative, Chrysiptera hemicyanea, the azure damselfish. The azure damselfish, however, has the vibrant yellow on its belly as well as its tail.
Growing up to 3 inches in length, these hardy fish are good for new and veteran reef chasers in a tank over 30 gallons. Yellowtail blue damselfish are also relatively easy to please with a variety foods. In the wild, they eat a variety of zooplankton, worms, brine shrimp, and copepods. They readily accept most frozen foods.
Much like other damselfish, the yellowtail blue damselfish one can be moderately aggressive, especially toward smaller/similar-sized fish and other damselfish. However, this species is more calm than most members of the Pomacentridae family. If you choose to keep more than one, aggression can be lessened or spread out if you have 3 or more. When keeping a yellowtail blue damselfish with other species of fish, provide multiple hiding places to break up territories and decrease aggression. They do like to have their
own cave and will spend most of their time defending it.