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The Green Chromis – The Non-Aggressive Damselfish You Need To Consider

One of the most popular saltwater fish you will find, the Green Chromis fish offers a gorgeous, colorful appearance and an extroverted personality that makes it the star of the freshwater aquarium.

This saltwater fish species has been on these scene for well over 30 years. A member of the damselfish family, this fish is known for its playful, easygoing nature – a sharp contradiction to the aggression usually displayed by members of this family.

If you’re new to keeping saltwater fish species, the Green Chromis fish could be the perfect introduction to the hobby. Here are some tips on how to successfully raise this fish species – no matter how much (or how little!) experience you might have.

Green Chromis

Green Chromis Background

Green Chromis 1
Photo by Djtronixgt

Also known as the Blue Green Chromis, this popular saltwater fish is referred to scientifically as Chromis viridis. These fish are found in the wilds of the Indo-Pacific, typically spending their days in protected environments like coral reefs and lagoons.

These are shoaling fish, preferring to be around other peaceful members of their species. These fish are found in the shallow reefs of the South Pacific as well as in the Indo Pacific Ocean. As a shoaling species, they will spend their days in shallow waters of around a meter – but will venture as far as twelve meters deep into the water.

Green Chromis spend much of their time hanging around coral formations. They will swim at all levels of the water column, but tend to hang out mostly in the middle.

Green Chromis Appearance And Behavior

Green Chromis 2
Photo by Re Assunção

Green Chromis fish are relatively small, only growing up to four inches in length. They are perhaps best known for their vibrant shades of green, of which there are plenty to choose from. They have oval-shaped, slender bodies along with distinctive forked tails. They are quite dazzling to look at when they shoal, as they will produce flashes of iridescent green light as they move around in large groups.

These fish are known for their peaceful demeanors. In addition. They are relatively easy to care for, particularly if you already have a saltwater community or reef environment in your tank. These fish are some of the most active swimmers you will find, spending most of their days in the middle water column.

They are shoaling species, but if you keep a group of multiple Green Chromis, know that there can occasionally be bullying among members of the group. Therefore, you should keep them in groups of at least six to prevent bullying. These social fish should never be kept on their own, as this can lead to issues in their health.

These fish vary in color from pale blue to light green. They have dense, compacted bodies with forked tails. This gives the fish a striking appearance! Males, however, will turn a more pale, yellow tone with black tails during the mating period.

In captivity, most Green Chromis fish will grow to around three inches in length. In the wild, these fish are somewhat larger, reaching lengths of four inches. Because they are relatively small, you can keep them in small aquariums.

These fish are often mistaken for Black Axil Chromis, which are closely related. However, the latter species has a longer body as well as a black spot on its inner pectoral fin. While these active fish are members of the damselfish family, which are known for their aggression, Green Chromis fish are exceptions to this rule. They are incredibly peaceful and can easily be kept with multiple other community fish.

Green Chromis fish love to play, and are fast swimmers that will chase each other around the tank. They prefer to swim among the coral and will also often sleep here. Make sure you have lots of coral in your tank! You might occasionally notice your Green Chromis fish behaving aggressively to each other, but this usually only occurs during periods of spawning.

If you plan on keeping Green Chromis fish for the purpose of breeding, just keep an eye on them to make sure they don’t act aggressively toward each other.

Green Chromis Tank And Water Requirements

Green Chromis 3
Photo by Re Assunção

Try to mimic the Green Chromis fish’s natural environment as closely as possible when you are setting up its tank. Because these fish spend so much time in coral formations in the wild, you should do your best to add coral to their aquarium when they are in captivity, too. They will use the coral as a hiding spot, a playground, and a home. If you’re new to keeping corals, a good choice is Acropora.

The Blue Green Chromis fish will swim around for much of the day, spending its time in the middle of the water column. One of the more active fish in your aquarium, this species should be kept in an aquarium that is at least 30 gallons or more in size. A shoaling group will need at least 60 gallons.

The water temperature of your tank should be warm, with an ideal range between 72- and 82-degrees Fahrenheit. The pH should be between 8.1 and 8.4 and the specific gravity should be 1.023 and 1.025. You should keep plenty of coral in the tank, as well as lots of planted sections that have lots of algae for your fish to nibble on.

These fish don’t care a lot about the current or level of water flow. Try to make sure it’s not too fast, but otherwise these fish won’t be bothered if the current is a bit faster or slower.

The most important factor in keeping your Green Chromis fish healthy is that you should make sure the tank is kept clean and tidy. A smaller tank will require a 15 percent water change every other week. This rule applies to tanks that are thirty gallons or smaller. Larger tanks (such as those larger than sixty gallons, or those used for shoaling groups), should be subjected to a 30 percent change once a month.

What Do Green Chromis Eat?

Green Chromis 4
Photo by howie516

Green Chromis fish are omnivores. They will eat both plant and animal matter. In the wild, these fish eat everything from mysid shrimp to zooplankton and even algae. They will also eat phytoplankton, unhatched fish eggs, larvae, copepods, and more. They are opportunistic, nibbling on anything they can find.

Therefore, it is important that you provide them with a wide variety of foods in your tank. They are voracious eaters and will consume just about anything you put in front of them. From flakes to pellets, frozen vegetables to live meats, you can feed these fish just about anything.

Good choices of frozen foods include mysis shrimp and krill. Another option is a liquid vitamins, which will help them stay colorful, but you can also enhance the colors of your fish by feeding them lots of herbivore flakes and diced vegetables.

Generally, you should be feeding your Green Chromis fish about three times a day. Feed small portions, as feeding them large portions too often can cause the rotting, uneaten food to diminish the pH levels and water quality in your tank. If you have a small tank, you might want to consider feeding less often than three times per day.

Green Chromis Tank Mates

Green Chromis 5
Photo by Boris_44

You can keep Green Chromis fish with just about any other kind of fish. Choose other peaceful community species like Butterflies, Basslets, and Blennies. While you can occasionally keep them with other moderately aggressive fish species, like tangs, you should always remember that the larger the fish is, the more likely it will be that your fish is bullied, or worse – viewed as prey.

When your Green Chromis fish are being bullied, they will spend most of their time in the top corners of the tank. If you see this happening on a regular basis, you know you will either need to remove the Green Chromis fish or the bully himself.

Of course, you are always safe keeping Green Chromis fish together, and this is quite a rewarding thing to do. They will produce vibrant displays of color as they swim about together in the water column. Remember that a healthy school of Green Chromis fish requires at least six fish.

Just as with other species, Green Chromis form a pecking order quote quickly. The most dominant Green Chromis fish will become the leader, while the others will be more submissive.

Common Green Chromis Diseases

Green Chromis 6
Photo by howie516

While Green Chromis fish are relatively hardy saltwater species and not prone to any abnormal diseases, there are some issues to which saltwater fish in general are prone. You will want to get into the habit of monitoring your fish and keeping an eye out for any abnormalities to make sure your fish stay healthy.

Providing your fish with a healthy, varied diet along with good water parameters and regular cleaning is the best way to make sure your Green Chromis fish stays healthy. However, sometimes situations will be out of your control and your fish will get sick despite your best efforts.

Some of the most common disease in a saltwater fish tank are caused by bacteria. While not all bacteria are bad, some bacteria can take over in a fish tank and reproduce rapidly, causing a myriad of health issues among your fish.

Fin rot is one of the most common, and when it occurs on a Green Chromis, it’s one of the most devastating. After all, these fish are known for their elegant fins, and it’s a shame to see them destroyed in this way. Fin rot is a bacterial infection that causes the fins to erode away. It can cause gill bleeding at its most advanced stages, too.

To prevent fin rot, remove any uneaten food immediately and conduct partial water changes on a regular basis. You may need to change the activated carbon in your filter, too. In some cases, antibiotics like Augmentin can help get rid of fin rot in your fish tank.

Viral diseases are also common. Cauliflower is one of the most common, and there is not a great treatment available to address it in a saltwater tank. You will need to isolate the fish and allow its immune system to get rid of the infection. Quarantining the fish is imperative, however as this can take some time and you don’t want the disease to spread to your other fish in the meantime.

Another common disease that can affect Green Chromis fish is Marine Ich. Also known as white spot disease, this is a treatable illness if it is caught and treated in a timely fashion. Marine velvet is another common, yeti unfortunate, illness, and this is caused by a parasitic skin flagellate. One of the most common illnesses in a marine aquarium, it moves quickly and attacks the gills of your fish.

All of these diseases can be treated with proper water quality and tank cleanings. A good rule of thumb is to treat your Green Chromis, though an inexpensive and easy to care for fish, as one of the most finicky and expensive saltwater fish species. This way, you will be sure to provide it with the ideal water parameters and varied diet it needs to stay healthy.

Breeding And Life Spans Of Green Chromis

It is not as easy to breed Green Chromis fish as it is other fish species in captivity. It can be relatively difficult to breed them in that they spawn every two weeks. Make sure you are careful about the species you house with your Green Chromis, as some species, like crabs, will eat damselfish eggs.

To breed your fish successfully, you will need to set up perfect water parameters and make sure there are no potential egg or fry predators in the tank. These fish spawn at temperatures between 79- and 83-degrees Fahrenheit, and will scatter their eggs over the nesting site, often referred to as an algae mat. You can make this with sand or a piece of sponge.

The male will establish his territory beneath the school of other Green Chromis. He will circle a female and, if she is ready, she will allow him to lead her to the pawning site. THen, he will rub his papillae on the mat and the female will also do this, depositing her eggs. The male will do this repeatedly with other females until the nest is full.

Each egg will be less than half a millimeter in length. They will attach to the algal mat, where the male will guard them and keep them ventilated until they are ready to hatch. He will occasionally eat other eggs that have gone bad so that they do not contaminate the clutch.

Eggs typically hatch within three days, with the larval stage lasting up to two months. Eggs and larvae are quite small and difficult to care for, so while it may be easy to initiate the breeding process, caring for the young is an entirely different story and should only be attempted by expert fishkeepers.

Is A Green Chromis For You?

If you’re looking for a unique new fish to add to your saltwater aquarium, the Green Chromis fish might be the right choice for you. A vibrantly colored members of the damselfish family, this unique fish is a peaceful alternative to other damselfish. It will keep itself quite busy, producing a gorgeous display of color as it moves with other members of its shoaling groups.

Why you’ll need to make sure that you only house your Green Chromis fish with other non-aggressive species of community fish, there is little else you need to do to make this elegant fish feel right at home.

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