Rainbow Wrasse Fish Care Guide (Coris Julis)


Common Name(s)Rainbow Wrasse, Mediterranean Rainbow Wrasse
Scientific NameCoris Julis
OriginNortheastern Atlantic Ocean to the Mediterranean Sea
Temperature60-70°F (16-21°C)
SizeMale grow up to 10 inches
Female grow up to 6 inches
Minimum Tank Size55 gallons
Food & DietCarnivorous
Lifespan2-4 years
Water pH8.1-8.4
Tank MatesGroupers, Angelfish, Hawkfish, and Triggerfish
BreedingPelagic spawning fish
DiseaseMay be susceptible to ich and dropsy.
Rainbow Wrasse
Rainbow Wrasse (Coris julis)

Rainbow Wrasse Facts

  • Juveniles specimen of female Rainbow Wrasse can grow and mature into adult males. The females retain their juvenile coloration, while the mature males take on brighter colors.
  • Rainbow Wrasse reach maturity at about 1 year old.
  • Rainbow Wrasse are carnivorous fish that will hunt small invertebrates that live on the ocean floor. They will eat gastropods, and crustaceans.
  • Rainbow Wrasse are considered semi reef safe as they will hunt and eat the creatures that live on the reef, but they will not eat or go after the coral itself.
  • Rainbow Wrasse get more aggressive the older they get.
  • It is important to provide Rainbow Wrasse a sandy substrate since they bury themselves in the soft sand to sleep and de-stress.

Rainbow Wrasse Care

Rainbow Wrasse (Coris Julis) are an interesting, brightly colored fish. Their color changes once they mature. Interestingly, both juvenile males and females can mature and grow into adult males. The Rainbow Wrasse has a long torpedo body shape. The adult males can have a green, blue, or brown body with a white belly. The males also have bright, jagged, orange bands on their bodies. Both male and female Rainbow Wrasse juveniles have a dull brown color with yellowish sides and whitish bellies. The mature females keep their juvenile coloration.

Rainbow Wrasse can be found hunting during the day, but they bury themselves to go to sleep at night. Smaller Rainbow Wrasses will bury themselves, while larger Rainbow Wrasse will wedge themselves in between the crevices.

Food & Diet

Rainbow Wrasse are carnivorous fish. In the wild, it feeds on small invertebrates that it can find on the bottom among the sea grass and rocks that it hides in. They are not picky eaters. They will eat isopods, sea urchins, shrimps, and small gastropods. Similarly, in captivity they will hunt and eat a variety of crustaceans, worms, and gastropods.

Rainbow Wrasse are considered a reef safe fish as they will not eat your coral. However, they may damage it while it is going after gastropods and other small reef creatures. Rainbow Wrasse will not eat your plants. In captivity, you will want to feed them a varied diet that is rich in protein. Their diet should consist of high quality flake or pellet food, supplemented by meaty frozen foods. 

Tank Setup

These are active fish that require sufficient space to swim and hunt. Rainbow Wrasse require a minimum tank size of 55 gallons. If the aquarium has a lot of objects that may obstruct the swimming area, a tank that is larger than 55 gallons may be required. In addition to the gallons of water that the tank holds, the tank dimensions are important as well. Since they are active fish, longer tanks are recommended as opposed to taller tanks.

Coming from the ocean, Rainbow Wrasse require a pH of 8.1 to 8.4, and a temperature range of 60-70°F.

When setting up a tank for your Rainbow Wrasse, you will want to mimic its natural habitat as closely as possible. They are most comfortable in environments with places to hide such as long sea grasses and rock structures. 

They will also require a soft sandy substrate. Make sure the sand substrate is deep enough so that they can bury themselves. Rainbow Wrasse will bury itself in the sand when it is tired or stressed.

When adding rocks and other hardscapes to the tank, make sure that they are secure. Rainbow Wrasse may attempt to rearrange rocks as they see fit. Smaller objects may be moved by the fish without causing any safety concerns. However, larger objects that are not secure can become a safety concern.

Coris julis (Mediterranean rainbow wrasse) 

Tank Mates for Rainbow Wrasse

Rainbow Wrasse are territorial fish, so their tank mates should be selected with caution. Significantly smaller fish are not advisable to keep as tank mates. Rainbow Wrasse are great hunters, and they will prey on small invertebrates and fish that are in the same aquarium.

If you want to keep other species of fish with your Rainbow Wrasse, choose fish that are larger and slightly aggressive so that they will not be hunted by the Rainbow Wrasse.

Larger fish will most likely be able to defend themselves from the Rainbow Wrasse. Groupers, Angelfish, Hawkfish, and Triggerfish are good choices for an aquarium that also houses Rainbow Wrasse.

Are Rainbow Wrasse Aggressive?

Rainbow Wrasse are aggressive fish, and they will get more aggressive as they mature. They are carnivorous hunters, and they will hunt and eat smaller fish in your aquarium. Rainbow Wrasse will also go after snails in your tank, or other small invertebrates that live on your reef.

If you are planning on placing Rainbow Wrasse in a community tank with other fish, do so with caution and proper research. If there are smaller fish in the tank, they may become prey.

Size & Lifespan

Male Rainbow Wrasse can grow up to 10 inches at full maturity. In contrast, females only grow up to approximately 6 inches in size.

Rainbow Wrasse have a lifespan of 2 to 4 years. If they are properly taken care of, they can reach this age even in an aquarium.

Where Do Rainbow Wrasses Live?

Rainbow Wrasse are can be found in ocean waters from Sweden to Senegal. They like to hide in sea grasses and rocks close to shore, and they will hunt and feed off of small invertebrates from the ocean floor. They can be found in open waters while they are spawning as well. At night, you can find the juveniles buried in the sand or the mature fish wedged into crevices. It is said that the Rainbow Wrasse is the last fish to come out in the morning.

Are Rainbow Wrasse Reef Safe?

Rainbow Wrasse should be placed in reef tank with caution, since they are not considered totally reef safe. While they do not each the coral or plants, they can destroy the corals and reef setup while hunting for their food. They regularly hunt and eat small crustaceans and gastropods that live among the reef.

Keep in mind that the Rainbow Wrasse do tend to get more aggressive as it ages, so the potential of them causing damage may increase as they mature.

However, some owners of Rainbow Wrasse have mentioned that the fish will not bother other fish or cause damage to the reef as long as they are well fed and there is adequate space.

Rainbow Wrasse Breeding

Breeding Rainbow Wrasse can be tricky. Rainbow Wrasse juveniles all begin life as females who can then mature into males. You will want to make sure that you have mature Rainbow Wrasse before you choose your breeding fish. Rainbow Wrasse mature at roughly one year old. If you place two juvenile Rainbow Wrasse together, they may both choose to remain female.

Rainbow Wrasse, like many other species around coral reefs are known as pelagic spawning fish. This means that they will release their sperm and eggs into the open sea. This usually happens near the surface of the water, and above the reef. Rainbow Wrasse have planktonic larvae which means that the larvae will float in the open water until they develop. Once the male and female are done spawning, they will swim off. They provide their offspring with no parental care.

Rainbow Wrasse Disease

Rainbow Wrasse can be susceptible to the same ailments as other saltwater fish, such as ich or dropsy.

It is better to prevent these ailments from occurring rather than to treat them as they appear. There are a few ways you can protect your aquarium and fish. Start by keeping their water clean, and perform regular water changes. You will also need to monitor your aquarium’s water parameters often for changes. If you are purchasing fish, you will want to make sure that you are purchasing them from a reputable seller. This will give you the best chance of receiving a healthy fish. Quarantining new fish is recommended as well. After a few weeks, you will be able to tell if your fish is healthy enough to add to your community setup. A rich, varied diet is also key in keeping your fish healthy.

Where to Find Rainbow Wrasse for Sale

You can find Rainbow Wrasse for sale online for around $30 to $50 USD. It is advisable to purchase healthy fish from a reputable seller, even if this means that they are priced at a slight premium.

Are Rainbow Wrasse Edible?

Rainbow Wrasse are edible fish, but there is no demand for them commercially.

Fish Laboratory

With decades of collective fishkeeping experience, we are happy to share the knowledge that we've picked up along the way. Our goal at Fish Laboratory Aquatics is to keep publishing accurate content to help fishkeepers keep their fish healthy.

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