This Blue Damselfish data sheet gives you basic information about the common names, scientific names and water parameters required by this species. In addition, you can find Blue Damselfish information such as diet, determining sex, breeding, distribution and compatibility. - because there's always time for reefing.
Blue Damselfish (Chrysiptera cyanea)


Scientific Name: Chrysiptera cyanea


Alt Scientific Name:


Common Name: Blue Damselfish


Alt Common Name: Blue Damsel, Blue Devil, Blue Devil Damselfish


Group: Damselfish (Damsels/Clownfish)


Family: Pomacentridae


Distribution: Indo-Pacific, Australian Pacific


Adult Size: 2.5 inches (6.4cm)


Minimum Tank Size: 10 gallons


Temperament: Like all damselfish, they can be territorial and aggressive, especially as they get older. These can be kept in groups if you are careful about the sex ratio, one male to several females. Can be kept with other larger fish but watch them closely to be sure their aggression doesn't become destructive.


Care Difficulty: 1/10

Very Easy
Very Difficult


Reef Safety Score : 3/3

Not Safe
High Risk
Low Risk
Reef Safe


Temperature Range: 75°F - 82°F



pH Range: 8.1 - 8.4



Salinity Range (specific gravity): 1.02 - 1.026



Diet Information: Omnivorous - does well with marine flake or pellet foods.


Additional Information : The Blue Devil Damselfish, also known as the Blue Damselfish, is the Molly of saltwater aquariums. It is a very colorful, hardy, and active fish. The female is all blue; the male has an orange tail, and is known by the common name of Orangetail Blue Damselfish. In the wild, Blue Devil Damselfish are found throughout reefs, usually busy defending a small territory. The Blue Devil Damselfish has the ability to hide in a hole or crevice and darken to an almost black color. This usually happens when it is threatened. After the perceived threat is gone, it will turn electric blue in a matter of seconds. The Blue Devil Damselfish is somewhat aggressive, so its housing should be able to easily accommodate multiple specimens. It is a good fish for beginners, and makes an ideal companion fish for a saltwater tank of over 10 gallons, and as a great companion for reefs and invertebrates. As the fish matures it may become aggressive, causing problems with the selection of other species to be added to the aquarium. If keeping with other damselfish, provide multiple hiding places to break up territories and decrease aggression. The Blue Devil Damselfish diet should consist of flaked and frozen foods, and herbivore preparations. The Blue Devil Damselfish is probably the best selling marine fish in the United States. Its hardiness and small size make it the most common fish among beginning hobbyists.


Tank Mate Compatibility : Use caution when selecting tank mates. Avoid keeping them with other damsels but if you do, introduce at the same time to limit territorial aggression. May harass other tank mates that come into their territory.


Breeding Information: Breeding is possible in home aquariums provided a male and female pair can be achieved.


Determining Sex: Blue Damselfish are sexually dimorphic. The females are entirely blue without any yellow or orange coloration, some females depending on localities have a black ocellus on the lower posterior part of the dorsal fin. Also they have nearly translucent fins (see photo at the top of this page), versus totally blue fins in males.


Primary Area in Tank: All over.



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