Blue Green Chromis (Chromis viridis): Fish Species Profile

Characteristics, Origin, and Helpful Information for Hobbyists

Blue green chromis fish with light blue and silvery scales

The Spruce / Adrienne Legault

Although the Blue Green Chromis fish (Chromis viridis) belongs to the damselfish family (a group of fish generally known for being somewhat aggressive in saltwater fish tanks), the Chromis is an extremely peaceful inhabitant of saltwater aquariums. With an iridescent, light blue-green colored body, Blue Green Chromis are gorgeous fish to keep in a saltwater aquarium. They enjoy swimming the length of the tank, which makes for a shimmering addition of color and movement as they dart about, especially when you keep a school of three or more Blue Green Chromis. The Blue Green Chromis is reef safe, bothering neither corals nor invertebrates, and gets along with most other fish (although Blue Green Chromis should not be kept with large, predatory fish, including eels, which could easily make a meal out of your Chromis). 

The Blue Green Chromis is a relatively inexpensive, easy to care for, and hardy little fish. Blue Green Chromis fish are active and inquisitive, so they are generally out and about in the tank. Blue Green Chromis are small, but these fish are fun to watch. For all these reasons, the Blue Green Chromis is a great choice for beginners looking to add color and flash to a saltwater aquarium. 

Species Overview

Common Names: Blue Green Chromis, Green Chromis, Blue-Green Reef Chromis

Scientific Name: Chromis viridis

Adult Size: 4 inches

Life Expectancy: 8 to 15 years


Family Pomacentridae
Origin Indo-Pacific
Social Peaceful
Tank Level All levels
Minimum Tank Size 30 gallons
Diet Omnivore
Breeding Egglayer
Care Easy
pH 8.1 to 8.4
Hardness 8 to 12 dGH
Temperature 72 to 78 F (22 to 25 C)

Origin and Distribution

The Blue Green Chromis fish is found in tropical and subtropical waters throughout the Indian Ocean and Pacific Ocean, including the Red Sea, Madagascar, Sri Lanka, Indonesia, the Philippines, Polynesia and the Hawaiian Islands, just to name a few locations. Blue Green Chromis live in coral reef areas and lagoons where they school in groups.

Colors and Markings

The color of the Blue Green Chromis is it’s crowning glory: a pale, shimmery light blue-green with no discernable markings. Male Blue Green Chromis will sometimes change colors during spawning—turning pale yellow—when they are ready to begin building a nest. Blue Green Chromis can grow to about four inches long, but juvenile Blue Green Chromis available for purchase at fish stores range from about half an inch to about three inches long.


A peaceful species, Blue Green Chromis can be kept with most other fish excluding large predatory fish that might eat the smaller Blue Green Chromis. When planning what fish to add to an aquarium, always add the most peaceful fish species first, working your way up to the most aggressive fish species you plan to keep. This helps limit fighting amongst fish due to territory issues. Blue Green Chromis do not bother invertebrates like shrimp and crabs, and these fish leave corals alone, so this species does well in reef tanks as well as fish only tanks.

Blue Green Chromis Fish Habitat and Care

Like most damselfish, Blue Green Chromis are quite hardy, making them a good choice for new aquarists. Unlike most damselfish, Blue Green Chromis are docile, preferring to stay out of any skirmishes amongst other fish in the tank. They enjoy swimming, so when keeping Blue Green Chromis in reef tanks, make sure your rockscape allows plenty of space for swimming in the middle to top of the tank. A group of Blue Green Chromis will school together. A small school of Blue Green Chromis darting about the aquarium is a dazzling sight to see, making this species a great addition to any saltwater aquarium. Some aquarists recommend keeping odd numbers of schooling fish like Blue Green Chromis (for instance, three, five, seven or nine fish). Even though Blue Green Chromis are small, if you wish to keep a school, your tank should be large enough to provide plenty of swimming space. Overcrowding a saltwater fish tank contributes to territory spats between fish, poor water quality and poor fish health.

Blue Green Chromis Fish Diet and Feeding 

Blue Green Chromis are omnivores, which means they eat both meaty and plant foods. However, the diet should primarily contain meaty foods like mysis shrimp, krill and brine shrimp. Feed a variety of mostly meaty foods plus some herbivore foods. Food options for feeding Blue Green Chromis may include flakes, pellets and frozen foods. Some aquarists like to soak fish food in a vitamin supplement made specifically for marine fish to bolster fish health and possibly to help keep the fish’s color vibrant. Feed your fish a few small meals per day, taking care not to overfeed. A surplus of uneaten food in your saltwater aquarium will contribute to poor water quality and unwanted marine algae growth.

Gender Differences

Male and female Blue Green Chromis fish do not have discernable physical differences. However, mature males will change color during spawning, turning a light yellow. 

Breeding of the Blue Green Chromis Fish

Blue Green Chromis will sometimes breed in captivity if aquarium conditions are ideal and there are no predators in the tank to eat the eggs. Blue Green Chromis males will prepare a nest in the sand bed into which more than one female will lay a large number of eggs. The males fertilize the eggs, then tend to the nest and protect the eggs until they hatch just a few days later. Unfertilized eggs or those that do not hatch are usually eaten by the male.

More Pet Fish Breeds and Further Research 

If you like the Blue Green Chromis fish, and you are interested in similar fish species for your saltwater aquarium, read up on:

Check out additional fish species profiles for more information on other saltwater fish.