Green Chromis can be the right pick if you want to adopt an easy-going saltwater fish. They belong to the family of damselfish. With shimmering bluish-green scales, they will make your aquarium a sight to behold.

These saltwater fish species have been in trend, considering their aesthetic gifts, easy maintenance, and decent pricing. Besides, if you prefer keeping a multi-species fish tank, then they are worth counting.

Even though Green reef Chromis possess a considerable level of compatibility, their semi-aggressive nature can hinder your fish parenting journey. Keeping this at the forefront, we present a comprehensive guide to making your journey smooth.

So, keep reading.

Green Chromis: An Overview

Quick Species Facts
Scientific Name ChromisViridis
Other Common Names Blue Green Chromis
Family Pomacentridae
Origin Indo-Pacific Region
Average Lifespan 8+ Years
Average Size 3-4 Inches
Type Saltwater Fish
Green Chromis Fish Care

Origin and Habitat

This marine species is found in and around the coral reef areas in the Indo-Pacific region. Thus, in their natural habitat,  blue-green chromis spread throughout the coral reefs across Hawaii, Madagascar, and the Philippines.

While talking about the nature of their habitat, they prefer relatively shallow water. Generally, they are found swimming in a depth of about 1 meter. When it comes to their habitat,   they prefer a depth of around 10 to 11 meters.

Since they go for slow-flowing water, you might spot a school of green chromis fish in regions like reefs and lagoons.

In fact, this species was marked in 1830 by Cuvier as a species of damselfish. Since then, the species has been a popular choice for aquarists.

Quick Fact: This damselfish species possesses a unique visual gift, which helps them collect crucial information from polarized light. With the help of this polarized vision capability, they can find food like zooplankton in the water column.

How Big do they Get?

Green chromis are typically small in their size. In the wild, they grow up to 4 inches in length. However, you can’t often find that size in captivity. Usually, a captive green chromis grows up to 3 inches in length.

One interesting fact about this species is that, although they don’t grow to be very long, they grow fast.

Appearance and Color

The mesmerizing hue of the blue-green chromis is the main factor behind their high demand. They are solid colored with a blue-green luster. This color may vary between bluish and pale green.

The magic concealed in their shimmering hue is that their color shows a changing nature while being revealed in different lighting. Based on the lighting, it might shimmer in white, greenish, or light bluish shades.

They have transparent fins emitting the same color revealed by their bodies. Plus, their fork-shaped tails contribute to enhancing their beauty. They are slender-bodied and shaped gradually bigger towards the head.

Remarkably the male changes its color during mating.

Maximum Life Expectancy

Usually, green chromis have a lifespan of up to 8 years minimum. As for their maintenance and tank environment, they can live up to 8 to 15 years, as they do in the wild.

Male Vs. Female

green chromis male vs. female

Unlike many other fish species, you can not find any distinctive difference between the males and females of this underwater species. The only distinction in view is the predominantly yellow coloration of the males with black tails during the spawning period.

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Quick Fact: Since they prefer inhabiting reef-specific areas, green chromis are quite reef-safe. In fact, coral reefs are necessary for their survival, providing them with the perfect space to live and hide.

Sale Price and Availability

Despite its widespread popularity throughout the market, green chromis are not extinct or endangered. The species is still widely available both online and offline.

You can find them to buy at around $14. It might go higher or lower according to the fish size. 

Care Guide

Quick Care Facts
Care Level Easy
Social Behavior Shoaling and sociable
Temperament Predominantly peaceful
Diet Omnivore
Breeding Not tricky under the right conditions
green chromis care facts

What do Green Chromis Eat?

These saltwater fish are omnivores. In the natural environment, they behave like scavengers, searching for food like larvae, mysid shrimp, algae, phytoplankton, zooplankton, and copepods. This shows that in captivity also, you need to feed your fish a protein-rich diet with varieties included. The good thing is that they will accept anything and everything you offer.

Recommended food for your green chromis includes the following –

  • Frozen food like mysis shrimp, brine shrimp, and krill
  • Pellets
  • Dry flakes
  • Nutrient-rich snacks
  • Meat
  • Fresh, finely chopped vegetables
  • Vitamin supplements

Pro Tip: It is good to feed green chromis 3 times a day. Still, you should check their feeding frequency based on the aquarium size. If you have a smaller fish tank, feeding them more than once in one day will deteriorate the water quality. However, if you have a bigger tank of 60+ gallons, you can provide them the ideal frequency of three times.

General Behavior

The green chromis is a schooling fish. Thus, although they belong to the damselfish family, they are not aggressive like other damselfish species. However, you can see an exception to their behavior during the breeding season.

Usually, they demonstrate peaceful behavior towards the other tankmates. This nature makes them community fish.

Plus, they are hyper-active, swimming across the tank in a school in a greenish-blue synchronization. The sight of this is really captivating.

When you add a school of them to your tank, you will see them making a pecking order. While forming this hierarchical order, they might show aggression. However, a sizable aquarium with plenty of space can solve this problem.


Green chromis breeding is not hard under convenient conditions. But what does it mean?

Well, it is a peculiar nature of this fish type that the presence of any predators in the tank leads them not to show any breeding or spawning-related behavior. The reason is simple – that will result in their eggs being eaten up by predators.

Other than that, spawning is possible in a community tank.

The only issue related to their breeding is that, as male-female differentiation is not possible before breeding, you will not know if you have both sexes in your tank.

This is only recognizable when they are spawning – through the yellow coloration of the males.

So, once you see any of your green chromis getting yellow, you can expect to welcome new fry.

The breeding process begins with the male. Let us have a detailed go-through on this topic.

  • First, the male builds a nest in the substrate.
  • Then, one or more females go there and lay eggs, and the male fertilizes them.
  • The eggs hatch within 2 to 3 days. The male guards the eggs until their hatching. It eats the unfertilized or dead eggs, protecting the others against damage.
  • Once the hatching ends, the male also stops guarding them.
  • But, the fry remains in the larval stage for up to 17 to 47 days. During this stage, the fry is quite vulnerable to attacks by predators.
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So, when breeding is not difficult, raising the tiny green chromis fry is difficult. To make it happen hassle-free, you can transfer the babies to another tank with special facilities to raise them.

Common Diseases

As they are known to be hardy fish, they remain healthy when surrounded by a healthy environment.

But, poor water conditions or other issues in the tank can cause illnesses.

The following list shows which diseases they are susceptible to.

  • Crypt or Marine Ich: a contagious disease mainly affecting the gills. As a part of the damselfish family, green chromis are susceptible to it. It is caused by the parasite called CryptocaryonIrritans.
  • Uronema: is a secondary infection caused by a parasite called UronemaMarinum. When attacked by this disease, the infected fish lacks appetite,   leading to fatality.
  • Marine Velvet: Caused by a dinoflagellate parasite, the marine velvet disease is another fatality to green chromis. It mainly attacks the gills of a fish. A lack of proper treatment can potentially lead the infected fish to suffocation.

For more extensive knowledge, visit this definitive guide describing fish-related diseases.

By providing your fish with a proper diet with healthy living conditions, you can keep them away from such diseases.

So make sure to keep the tank water within a perfect salinity level while at the same time keeping the ammonia and nitrate levels in check.

Tank Care

Quick Tank Facts
Minimum Size 30 Gallons
Water Temperature 72 To 82 degrees Fahrenheit
Water Hardness 8 to 12 dkH
Lighting Low
pH Level 8.1 to 8.4
Green chromis tank care guide

Ideal Tank Size

Considering that these ornamental fish are shoaling in nature, they need considerable space to roam around despite their small size.

The fish experts recommend a minimum tank size of 30 gallons for them.

However, this tank size is perfect for a couple of them. If you are planning to house a large school of around 6, you will need a tank of at least 55 to 60 gallons.

Tank Setup

First and foremost, they need a reef or marine set-up for their well-being. It is necessary to note that they are middle-water swimmers to replicate their natural habitat.

Now, let us learn how you can set up a tank effectively for your blue-green chromis.

  • Plants: Adding sea-friendly plants is recommended for your aquarium with marine species. You can go for plants such as red mangroves, green finger algae, Halimeda, etc.   Plants will help control the ammonia and nitrate levels, and algae are tasteful for their grazing.
  • Lighting: Lighting is not a primary necessity for a green chromis tank. This saltwater species does not prefer bright lighting. So, it is recommended to provide dim lighting in your green chromis fish tank.
  • Substrate: They spend most of their time around corals in the wild. Keeping these saltwater fish in captivity also requires imitating the natural environment they like. Thus, giving your fish the best possible environment, you can go for a sandy reef substrate. They are fond of coral reefs, where they spend hours without harming the coral.
  • Oxygen and Filtration: Your fish tank needs a stellar filtration system to keep it hygienic. Although this species does not produce a massive heap of waste and dirt, filtration is necessary to control the ammonia and nitrate levels of the tank to keep the pollution under control and maintain sufficient oxygen levels.
  • Decor: Decorating a green chromis tank involves sea plants and algae, as discussed before. In addition to that, you can go for live rocks and caves. While they are perfect for decoration, they also come in handy, providing them with many hiding places. However, it is also necessary to remember that being a busier fish, they need enough swimming space in the tank. If your decorations are overwhelming, they might be deprived of their swimming space.
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Pro Tip: You must be wondering how many green chromis you should keep. It is recommended to add at least 6 fish to a tank, considering their pecking behavior.

Water Parameters

This species is known to be a hardy fish. Despite that, maintaining a healthy water condition will make you escape the risk of getting sick or stressed fish.

With this in the forefront, keep the water temperature between 72 to 82 degrees Fahrenheit. Besides, the ideal pH level has to be between 8.1 and 8.4. On the other hand, the preferable water hardness is 8 to 12 dkH.

As it comes to be crucial for freshwater fish, the water flow is not as significant for saltwater fish like green chromis. However, considering that they prefer shallow water areas like reefs and lagoons, it is advisable to keep the water current low.

Finally, keeping a stable water level is remarkable to keep any fish happy, healthy, and stress-free.


This fish species shows peaceful social behavior. Although they might be somewhat aggressive while creating a pecking order within their school, they are community fish.

Considering this nature, you can add them to a community tank with other peaceful fish species. The following list mentions the preferable tank mates for this greenish beauty.

  • Blennies
  • Butterflyfish
  • Gobies
  • Basslets
  • Clownfish

If you choose to keep this species with any aggressive fish species like tangs, you must be careful to notice any behavior signaling hostility. As you already know, green chromis prefers to swim primarily in mid-water. Behavior like coming to the surface instead of swimming in the mid-water might indicate hostile behavior against them.

Plus, experts advise not to keep these small fish with eels or any other large fish species to prevent the unfortunate from happening.

Frequently Asked Questions

What does blue-green chromis kissing behavior indicate?

Kissing behavior in this fish species might indicate two types of things — breeding behavior and aggression. If you notice such behavior, you should be careful to observe if your fish are ready for breeding. If not, then it can be a sign of heavy aggression.

Is the constant dying of blue-green chromis in the aquarium natural?

Although a shoaling fish, this saltwater fish might become alarmingly aggressive. Thus, if your fish die one after another within a short span, you need to be mindful. It can be a consequence of this hostile behavior owing to creating hierarchy. Another potential reason for the death of your saltwater pets might be their tiny size when you bring them from the breeder.

Can green chromis produce sounds?

Sound producing is a characteristic feature of the coral reef fish family Pomacentridae. Green chromis, too, is not an exception. As a study reveals, like any other fish species belonging to this family, these luminous beauties also emit “calls in agonistic and courtship contexts.”

Final Thoughts: Should You Get Them Home?

Answering this question is pretty simple.

This fish species is worth adopting for your home aquarium for multiple reasons.

First and foremost, they take well care of the aesthetics of your aquarium with their magnificent blue-green reflections.

Then, this saltwater species doesn’t demand high expenses or intensive care and maintenance.

Usually, whenever you decide to start a new venture, your experience level becomes a crucial factor to ponder. However, when it comes to green chromis, it is not.  Whether you are a beginner or have a lot of experience, you can go for them.

And most importantly, if you look at the ornamental fish market, this species can be positioned at the topmost level considering their high commercial value.

So, you can own them without any worries. But, remember that they are happier when they are parts of a large shoal. Experts recommend adding at least six of them in a tank for their well-being. Adding six or more fish is preferable in controlling their aggressive behavior during their pecking order.

With all that in mind, you will make a successful fish parent of your green chromis school.

About the Author

Victoria Lamb

Victoria is a freshwater aquatics specialist, fish keeper, and amphibian enthusiast. She has had more than 6 years of experience caring for aquariums and keeping several fish species, and her home boasts of 3 aquariums and a garden pond. Her goal is to educate fish owners on raising healthy and happy aquatic pets. Career Highlights:…

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