Rainbow Parrotfish (Scarus Guacamaia): Ultimate Care Guide


The Rainbow Parrotfish (Scarus Guacamaia) is a beautiful and colorful fish that is found widespread across the Atlantic, Pacific, and Indian Oceans.  The Rainbow Parrotfish is mostly yellow with brown stripes near its eyes and mouth, which fade into varying shades of red towards its tail.  These striking colors make it difficult not to fall in love with this interesting fish.  Sadly, the Rainbow Parrotfish is near endangered, mostly due to humans.  We have overfished them (they are considered a delicacy to some) and we have destroyed their beloved mangrove nurseries.  Most of their community is found from Florida, Bermuda, the Bahamas, and down to Argentina.  They live near reefs at depths of 2-27 meters.  These fish are often found in shallow waters, so maintaining the correct warm water temperature is important.  They are an essential part of reef ecosystems due to their feeding habits, but they also require specific care in order to thrive in captivity.  This blog post will provide you with all the information you need so you can give them a happy life at home!

Rainbow Parrotfish Facts

  • They have a unique beak-like mouth, hence the name Parrotfish.  Their teeth are among the strongest in the world, made of fluorapatite; one of the strongest biominerals.  Parrotfish have about 15 rows of 1,000 teeth all fused together!  They use their beak to scrape algae from rocks.  Their teeth are also helpful in consuming coral.
  • Adult Parrotfish eat coral and their waste comes out as sand.  They produce up to 200 pounds of sand a year!  The white-sand beaches of Hawaii actually come from the poop of the Parrotfish!  Scientists estimate that 80% of the sand in coral reefs comes from the Parrotfish.
  • When they go to sleep, they spit out mucus and spread it around their bodies.  They become enveloped in a mucus cocoon.  It is believed that this keeps them from being smelled by predators, especially moray eels.
  • Most of them are considered protogynous hermaphrodites, which means these Rainbow Parrotfish can switch sexes.  When they do this, their colors can change.  This is triggered by their hormones.
  • The Rainbow Parrotfish is the largest species of the Parrotfish family, of which there are 90 different species!  The Rainbow Parrotfish can weigh up to 45 pounds!
  • The Rainbow Parrotfish has been featured on Animal Planet’s “Tanked” TV show for its vibrant colors and unique shape.
Rainbow Parrotfish
Rainbow Parrotfish (Scarus Guacamaia)

Rainbow Parrotfish Care

Temperature for Rainbow Parrotfish

The Rainbow Parrotfish is a beautiful fish that requires an appropriate tank temperature.  If the water does not reach at least 79 degrees Fahrenheit, they may become sick or stop eating, resulting in a loss of color and a weakened immune system.

Water pH for Rainbow Parrotfish

The optimal water pH is between 8.1-8.4.  You do not want the water to be too acidic or too alkaline.  Water pH can affect growth, behavior, and appearance.  The correct pH can help them resist diseases and tolerate stress.

Rainbow Parrotfish Size

The average size for Rainbow Parrotfish (in captivity) is 1 foot long, but they can grow up to 3 feet in length!  They can weigh as much as 45 pounds!  You should always keep an eye on your fish tank because it’s possible that your fish will need more space as they get bigger.

Rainbow Parrotfish Tank Size

The size of the aquarium for your Rainbow Parrotfish will vary depending on how many you want to keep together at one time.  Allow about 24 inches (60 cm) of length per pound (0.5 kg).  The larger the tank, the better, as these fish grow quickly!  The tank needs to be at least 55 gallons with the expectation to upgrade as the fish get bigger.  You may want to consider a 200-gallon tank from the outset.

Rainbow Parrotfish Food & Diet

Keeping your pet Rainbow Parrotfish healthy is one of the most important things you can do for them.  They are herbivores and the best diet for a Rainbow Parrotfish includes many different types of marine plants and invertebrates, such as seaweed, algae, plankton, copepods (small crustaceans), krill (tiny shrimp-like animals that eat phytoplankton), and other zooplankton.  They also eat coral, but this must not be their main source of food.  With this type of diet, they will be able to get the nutrients they need to survive in captivity.

Rainbow Parrotfish Lifespan

Their expected lifespan is 5-15 years, but that can be shortened quite a bit when in captivity.

Rainbow Parrotfish Tank Mates

Compatible Tank Mates for Rainbow Parrotfish

They get along with most fish and are non-aggressive.  They are quite shy, peaceful, and friendly, preferring to hide behind rocks and in caves.  Some good options for tank mates for Rainbow Parrotfish are other peaceful types like clownfish, angelfish, hogfish, butterflyfish, boxfish, and batfish.  They are happier when they are in groups.  It is good to consider other tank mates if you don’t plan on having more than one Parrotfish.

Incompatible Tank Mates for Rainbow Parrotfish

Any smaller fish are incompatible because the Rainbow Parrotfish might prey on them.

Tank Setup for Rainbow Parrotfish

Aquarium Filter

You will need a powerful aquarium filter, such as a canister filter.  They are usually more expensive, but they can go much longer in between cleanings.  The most common cause of death among Rainbow Parrotfish is suffocation when their gills become clogged with food or other particles found in the water column.  This happens often if you feed them too much or if there isn’t enough oxygen coming into the water due to lack of circulation or a filtration system failure.  You definitely don’t want this to happen to your Parrotfish.

Aquarium Heater

You will need an appropriate size aquarium heater for your tank.  Be sure to research the correct heater according to the size of your tank.  As we discussed earlier, lower temperatures can result in a loss of color and a weakened immune system.  It is good to check your water temperature weekly to make sure your heater is working correctly.

Aquarium Lights

Aquarium lights are important for keeping your fish regulated to a normal day and night cycle.  They are also essential for the growth of coral and plants.  Research the best lights for your Rainbow Parrotfish as you don’t want them to be too bright.  Most aquarium lights run for 8-12 hours a day.

Aquarium Substrate

Substrate is not just for making your tank look pretty.  It serves an important role in the nitrogen cycle.  You can use sand or gravel, whatever meets your preferences.  And remember that your Parrotfish will create its own sand!

Plants and Hardscape

Real plants make the tank feel homier.  Rainbow Parrotfish feed on coral, so it is an excellent option.  Make sure there are plenty of rocks for the fish to hide behind and caves for them to hide in.  It is very comforting to them.

Breeding Rainbow Parrotfish

They are pelagic spawners, which means they spawn in the open sea near the surface.  The females release eggs and the males fertilize them by releasing sperm into the water.  The fertilized eggs float and eventually settle somewhere and wait to hatch.  The females’ hermaphroditic nature allows them to change sex and they do this when there are not enough males present.

Rainbow Parrotfish Disease

With improper care, the Rainbow Parrotfish has to deal with diseases that are not always easy to treat.  One of the most commonly seen diseases in Rainbow Parrotfish is Chromobacterium Violaceum, which causes ulcers on their skin.  Other common ailments for this species include Chloroquine Sensitivity Syndrome (CQS), Dermatophilosis, Skin Flukes, White Spot Disease (WSD), Fin Rot, and Marine Ich.  If your Rainbow Parrotfish has any signs of disease, you may need to check your tank settings, filtration and you may need to get some over-the-counter medication from a pet store or veterinarian.  It is very important to check your Rainbow Parrotfish for any signs of disease or suffering.

Where Can I Find Rainbow Parrotfish for Sale

Since Rainbow Parrotfish are near endangered, you will likely not be able to find them locally.  We have found some places online where you can order them.  The prices vary widely.  Here are some sources we found:

Pete’s Aquarium

Price: $38.99-$79.99, $59 Nationwide Shipping, Return and Replacement Policy, Located in New York

My Saltwater Fish Store

Price: $12.69-$379.99, $29 Nationwide Shipping, Return Policy, Located in Florida

You can also contact your local pet store as a resource to see where you can buy one. 

The Rainbow Parrotfish is a fascinating fish that deserves to be cared for properly.  They are not always easy to find in pet stores, but you can buy them online with some research and forethought.  A lot of consideration must go into whether a Rainbow Parrotfish is right for you and your lifestyle.  Keep in mind that they are near endangered and they are not easy to breed in captivity.  They require some time and effort that will be easy for an enthusiastic Rainbow Parrotfish owner!  However, this might not be the best choice for a new aquarium owner.  Consider the Rainbow Parrotfish care guide when deciding whether or not this beautiful species of fish would make an excellent addition to your aquarium!

Fish Laboratory

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

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