Blue Chromis (Chromis cyanea)

Updated August 5, 2019
Author: Mike - FishLore Admin
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The Blue Chromis is a member of the damselfishes and given their hardy nature they can be a good choice for a saltwater beginner. In fact, many hobbyists use the Blue Chromis to cycle new tanks. This is not recommended and there are much better ways to cycle a new tank these days with the use of live rock in saltwater aquariums.

They need to be in small schools (shoals) of 6 or more and are a very active fish.

Blue Chromis Blue Chromis

They are a brilliant blue color with a black outline along the bottom of the dorsal fin and around the caudal fin.

Blue Chromis should do well in most tank setups, but you don't want to keep them with overly aggressive tank mates or fish large enough to eat them. Keep them in a small school and they should do fine. You may notice a pecking order develop among the school and that is normal behavior. The Blue Chromis is sometimes sold as a "dither fish" because it is out in the open so much and it makes the shy fish in your tank more at ease.

They eat zooplankton on the reef and will accept most types of marine fish food including frozen, freeze dried, vitamin enriched flakes and live foods. Give them a variety of foods for optimal coloration.

They seem to be fairly disease resistant but you still need to take proper pre-cautions and use a quarantine tank before introducing them into your main tank.

An interesting note about this species is that young Black Snapper, Apsilus dentatus (Lutjanidae) mimic the colors of the blue chromis.

Blue Chromis Care

Scientific Name : Chromis cyanea

Common Names : Blue Reef Chromis

Care Level : Easy to Moderate, good for a saltwater beginner.

Size : Up to 5 inches (13 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 : Western Atlantic, Caribbean. Usually found on the reef slope at around 10 meters.

Temperament / Behavior : They like to be in small schools (shoals) of 6 or more and can take care of themselves with larger, more aggressive tank mates. However, tank mates much larger, like Triggers, may make a snack out of them. They are extremely active and will make an interesting addition to the top of the tank. This fish is considered reef tank safe.

Breeding : Sometimes bred in saltwater reef tanks. Need a small school (shoal) and good water conditions. Get them ready by giving them live foods. Males should build a nest in the sand and court various females. The male will then watch the eggs until they hatch a few days later.

Aquarium Size : 30 gallon (114 liters) minimum

Blue Reef Chromis Tank Mates : They can make an excellent addition to most tanks with smaller species.

Diet / Foods : In the wild, they feed on zooplankton so try to give them a variety of marine foods. They should accept vitamin enriched flake foods, frozen and definitely live foods.

Tank Region : Usually top

Gender : Difficult to determine the differences between males and females.

Photo Credit : Photos copyright

Site References :

Fish Lore Forum : Blue Chromis Forum

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