Updated August 5, 2019
Author: Mike - FishLore Admin
The Blue Damselfish, also known as the Blue Devil Damselfish, is an extremely popular marine fish because it is readily available and because it is very hardy.
Although we don't recommend it, many hobbyists use the Blue Damselfish to cycle new saltwater tanks. There are better, more humane ways to cycle a tank such as using live rock to cycle your saltwater aquarium.
They get the nick name Blue Devil because of their personality. They can be very belligerent with other fish in the tank, especially new arrivals. They are very bold and can hold their own with larger fish and may even go after your hand if it approaches their territory. They didn't get the memo about them only being a few inches in size. We'll call it the mighty mouse syndrome.
As mentioned previously, Blue Damsel fish will develop their own territory in the tank. Having live rock in your aquarium will help make them comfortable and it will provide them with hiding places. You can get away with keeping multiple Blue Damselfish in the same tank if you introduce them at the same time. Because of their "anger management" issues it is a good idea to introduce them last into your setup.
They are not very picky when it comes to fish food and should accept most foods that you give them. Try to give them a varied diet of live, frozen, freeze-dried and vitamin-enriched flake foods.
They seem to be very resistant to most saltwater fish disease but you still need to take the proper pre-cautions and use a quarantine tank before introducing them into your main tank. After they've been in quarantine for two weeks or so and you notice no signs of illness you can acclimate them into your display tank.
Blue Devil Damselfish Care
Scientific Name : Chrysiptera cyanea
Common Names : Blue Devil Damsel
Size : Up to 2.5 inches (6 cm)
Life span : 5 years or longer
Water Parameters : pH 8.1 - 8.4, Temperature : 75°F - 82°F (25°C - 28°C), Specific Gravity : 1.020 - 1.025, Carbonate Hardness (dKH) : 8 - 12°
Origin / Habitat : Indo-Pacific, Australia, Pacific - found in shallow waters of the West Pacific.
Temperament / Behavior : Can be very aggressive with other fish that encroach upon their territory. Even much larger fish can get harassed when swimming past their territory. Use caution when introducing new tank mates in a tank already populated with blue devils. Blue damsel male on male aggression is common.
Breeding : This fish has been bred in the home aquarium.
Aquarium Size : 30 gallon (114 liters) minimum
Tank Mates : 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.
Diet / Foods : Omnivorous, try to give them a variety of marine foods. They should accept vitamin enriched flake foods, frozen and live foods.
Tank Region : Usually stays close to its chosen territory in the live rock or any other tank decor that can provide shelter.
Gender : Females have the black spot on the dorsal fin, whereas males may not have the black spot.
Photo Credit : Photos copyright JJPhoto.dk
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Azure Damselfish Comments and Tips
I initially bought 3 of these to help the aquarium cycle in my new saltwater tank and they lived through the cycle. They are definitely a tough fish. The problem though is that they are not good neighbors with any other fish that I place in the tank. I'm regretting getting them because the pester all the other fishes when they swim by their territories.
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Three Stripe Damselfish
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