Chrysiptera parasema: a Gem of a Damsel

Less attitude and a brilliant blue body with bright yellow tail make C. parasema quite an appealing little damselfish!

Less attitude and a brilliant blue body with bright yellow tail make C. parasema quite an appealing little damselfish!

Ask the average marine aquarium hobbyist to identify the most aggressive coral-reef fishes, and the damselfishes of the family Pomacentridae are likely to be placed somewhere very close to the top of the list. For many damsel species, the reputation for belligerence is well deserved. However, there are some noteworthy exceptions — damsels that are actually fairly docile and apt to coexist peacefully with a wide variety of tankmates. Among them is the popular yellowtail blue damsel (Chrysiptera parasema).

Physical characteristics

C. parasema is truly a gem of a fish. Its body is a lustrous blue overall. Depending on the lighting over the aquarium, this coloration can take on brighter or deeper hues or even appear purple or almost black. As the common name suggests, the tail and caudal peduncle are bright yellow. In some specimens, yellow may also appear on the anal fin and the trailing edge of the dorsal fin. The maximum length for this species is not quite 3 inches.

A practically perfect beginner fish

Few species are better suited to beginners than the yellowtail blue damsel. C. parasema is remarkably hardy, so it can usually weather the occasional water-quality missteps that beginner’s are prone to, and it will readily accept standard aquarium fare. Owing to its diminutive size and the fact that it doesn’t demand a great deal of open swimming space, it’s also a great choice for smaller aquariums (down to about 20 gallons).

Foods fit for the yellowtail blue damsel

C. parasema is omnivorous, and, therefore, its captive menu should include a good variety of both meaty and algae-based foods. Mysid shrimp, brine shrimp, finely chopped seafood, pellets, flakes, and various frozen formulations for omnivores and herbivores are just a sampling of the foods it will accept. Again, feeding is a snap and hunger strikes are rare with this species.

Suitable tankmates

While the usual conundrum when choosing tankmates for a damsel is finding species that won’t be tormented by the damsel, that problem is sort of turned on its head with C. parasema—you have be more wary of introducing aggressive tankmates that will pick on the yellowtail.

Now, that doesn’t mean that C. parasema is a complete Caspar Milquetoast. It’s a damsel, after all, and the rules of appropriate order of introduction still apply. Extremely shy, retiring species—especially those that are very similar in size and color, should be introduced before the yellowtail.

With respect to conspecifics, C. parasema is one of the few damsels that can be kept in groups. However, I would recommend attempting this only in larger systems with lots of rockwork to provide ample hiding places and disrupt the damsels’ line of sight.

The ideal reef resident

Not only is C. parasema a perfect choice for beginners, but it’s also an ideal candidate for reef systems. This diminutive gem of a damsel is completely inoffensive to corals and other sessile invertebrates and will have a minimal impact on the system’s bioload.

Photo Credit: Moto@Club4AG


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About Jeff Kurtz

Jeff Kurtz is the Co-founder/Editor of Saltwater Smarts, former Senior Consulting Editor for Tropical Fish Hobbyist Magazine, and the aquarist formerly known as “The Salt Creep.” He has been an aquarium hobbyist for over 30 years and is an avid scuba diver.


  1. I disagree! I have 2 of these damsels and no other fish or inverts. Reason being…they will kill ANYTHING that I put in the tank with them, fish or inverts. I put 1 Peppermint Shrimp in my tank and they beat the hell out of him. I will never get another Damselfish again!

    • Hi Greg! By any chance, were the damsels the first residents of the tank? If so, this behavior may simply stem from the fact that they had a chance to claim the whole tank as their territory before other specimens were introduced (as I mentioned above, even though yellowtails are peaceful as damsels go, they’re still damsels nonetheless).

      You might try removing the damsels from the system temporarily, rearranging the rockwork/decor, and then introducing the other specimens. Once the newcomers have had a chance to lay claim to a niche, you can try to reintroduce the damsels (if you so desire). With the aquascape rearranged and the new specimens having staked out territories, the damsels will then be the “odd fish out” and should be less inclined to exhibit territorial aggression.

      Of course, I should also emphasize that within any given species, there will be exceptions to the general rule when it comes to behavior. Some individuals of a notoriously aggressive species may be surprisingly peaceful, or you might find specimens of a usually peaceful species that misbehave.

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