Blue Parrotfish (Scarus coeruleus) | Facts & Care Guide

Blue Parrotfish
Blue Parrotfish (Scarus coeruleus)

Blue Parrotfish Facts

Common NameBlue Parrotfish
Scientific NameScarus coeruleus

The Blue Parrotfish, known by the scientific name Scarus coeruleus, is a member of the parrotfish family and is an saltwater fish most often found in the tropical and subtropical waters of the western Atlantic Ocean and Caribbean Sea. The scientific name for the Blue Parrotfish comes from Latin and means blue fish. Within the parrotfish family (Scaridae), there are approximately 95 species, and the Blue Parrotfish is one of them.

The Blue Parrotfish are mainly blue in color and born with a yellow spot on their head that fades with age as they develop a bulging snout and more uniform blue hues. The juveniles are typically pale blue in color, while females are a range of blue shades, and males are usually blue-green with grey markings.

Beyond their size, the color of their scales makes it easy to identify their age and sex from first glance. Their body is covered with large, smooth scales, and they are the only member of their species with a uniform blue color that makes them easy to identify.

Role of Blue Parrotfish in Ecosystem

The Blue Parrotfish plays a crucial role in the ecosystem of coral reefs. Here are some key points about their role:

  • Algae Control: With an algae-centric diet, they help preserve the coral in reefs by removing algae that could potentially suffocate or harm the coral.
  • Coral Reef Health: They eat dead, algae-coated coral. This not only controls the length of their teeth but also reduces the amount of algae that could suffocate the coral.
  • Beach Formation: The undigested coral pieces they excrete get deposited as sand in these areas. They are responsible for the sandy beach formation in the Caribbean.
  • Group Foraging: They usually forage in a group of 500 individuals for spawning and deterring predators while feeding.

These fish not only contributes to the health of coral reefs but also to the beauty of the Caribbean beaches.


Blue Parrotfish are abundant in the southern region of the Gulf of Mexico and are the second-largest parrotfish species to be found in the Caribbean. They have been reported as far north as Maryland, the U.S.A, and as far south as northern South America. They are also popular in southern Florida regions, including but not limited to the Florida Keys. They enjoy living in coral reefs and shallow coastline waters up to 80 feet in depth and is native to Bermuda, the Bahamas, Jamaica, and Haiti.


The Blue Parrotfish can be expected to live up to 7 years in their natural habitat. However, they are likely to live a much shorter life if held in captivity, since they generally have difficulty adapting to captive environments. Please note that these lifespans can vary depending on various factors such as environment, diet, and care.


The Blue Parrotfish has several fascinating adaptations that help it survive in its environment:

  • Uniform Blue Color: The Blue Parrotfish is uniformly blue with a yellow spot on their heads that fades as they age. No other species has this uniform blue color as adults.
  • Beak-like Structure: They develop a large “beak” like other parrotfish that is used for scraping algae and small organisms from rocks. This beak-like structure is formed by their teeth being fused together.
  • Pharyngeal Teeth: They have pharyngeal teeth that grind ingested rocks into sand. This not only aids in digestion but also contributes to the formation of many sandy beaches in the Caribbean.
  • Group Foraging: They usually forage in a group of 500 individuals for spawning and deterring predators while feeding. This social behavior helps them protect themselves from predators.
  • Sex Change: These fish can undergo a sex change, with some females changing into brilliantly colored males.
  • Habitat: These fish inhabit coral reefs of depths ranging from 3-25m. Juveniles are usually found on Thalassia testudium beds (turtle grass) feeding on small benthic plants and other small organisms.
  • Diet: Their diet consists of small organisms found in the algae that they scrape off rocks. They are described as professional sand-suckers, due to their foraging of food amongst the sandy areas that surround the reef.

These adaptations allow the fish to thrive in their coral reef habitats.


Blue Parrotfish breed year-round but are most active in mating during the summer months from June to August and are typically recorded spawning at dusk. Both male and female reach sexual maturity between two and four years of age. These fish have some of the most complex reproductive systems among all fish species, being born as either primary males, secondary males who can change sex, or females who can change sex.

They mate in groups, and their social hierarchy relies on mating and reproductive habits. After mating, the female fish produce fertilized eggs that hatch in the water 25 hours after being laid.

There is little recorded evidence of parental instincts or behaviors related to this species, and their larva is typically left to survive on its own after birth. Juveniles most commonly inhabit seagrass and begin to feed on the grass, and small organisms, just three days after they hatch from their egg.  

Blue Parrotfish Care

Blue Parrotfish are not typically kept in home aquariums due to their large size, habitat requirements, and specific feeding requirements. Although they are generally known to be hardy fish in the wild, keeping them healthy in a captive environment can be a challenge. Since meeting these care requirements are not beginner-friendly, only experienced fish keepers should consider owning these fish.

Food & Diet

The Blue Parrotfish primarily feeds on algae. They extract the algae from chunks of coral that come from the reefs. They bite the coral with the teeth in their throats to take off the algae polyps. They spend 90% of their days feeding on excessive algae growth on coral. They also consume small benthic invertebrates in the sand. Occasionally, they eat small crustaceans that get in their way but they prefer a plant-based diet. They are also known to grind rocks and sand in search of food in their natural habitats. Due to their feeding habits, they are considered noisy eaters.

Even in captivity, the best food option for the Blue Parrotfish is the naturally occurring algae found on ocean rocks and coral. However, this can be difficult to maintain and replicate it in an home aquarium. When attempting to grow plants and rock algae for this fish, choosing the correct light setup would be important. Since the production of naturally grown food could be unreliable, finding an alternative algae-based food source that these herbivores can accept would be ideal. While they prefer a plant-based diet for the most part, they can occasionally be fed small crustaceans as well. They are known to feed on frozen brine shrimp and frozen krill.

Tank Setup

A Blue Parrotfish tank should be set up to replicate their natural habitat as closely as possible to limit stress and decrease disease risk. Sand is a good option for substrate, as it is a more natural alternative to gravel or stone. A capable aquarium filtration system, such as a canister filter, is need to maintain a reef aquarium large enough to sustain and ensure a clean habitat. To mimic the warm tropical environment, a reliable aquarium heater would be needed. The tank should also include a variety of rocks, plants, and hiding places.

Tank Size

Blue Parrotfish require a minimum tank size of at least 200 gallons. This will give the fish enough room to grow to its full size and maintain its health. As active swimmers, they need room to swim. In fact, they can reach speeds of up to 3.2 times their total length per second. They also need adequate space to hide, which will help support their natural behaviors.


Blue Parrotfish prefer water temperatures between 75 to 78 degrees Fahrenheit. As tropical fish, they require warm temperatures in order to maintain their health. When temperatures fall below their optimal range, it can cause a loss of vibrancy and will potentially weaken their immune system. This will leave them at a higher risk for contracting deadly diseases and infections.

Water Parameters

In order to keep Blue Parrotfish in captivity, maintaining water parameters that mimic their natural environment would be important. These water parameters include temperature, pH, and salinity.

Here are the optimal water parameters for Blue Parrotfish:

  • Temperature: 75 to 78 degrees Fahrenheit
  • Water pH: 8.1 to 8.4
  • Salinity: 1.020 to 1.025

Blue Parrotfish Size

The Blue Parrotfish is one of the largest species of parrotfish, and they reach 11 to 29 inches in length on average. There are records of these fish reaching maximum sizes of up to four feet long. At full maturity, they can weigh up to 20 pounds or more.

While specimen in the wild tend to grow to a large size, specimen in captivity that are kept in home aquariums tend to stay relatively smaller, within the average range.

Scarus coeruleus (Blue parrotfish)

Common Health Issues

Blue Parrotfish are generally considered to be hardy fish, but there are various conditions that may impact their health:

  • Stress-Related Diseases: They are prone to stress when their habitat is changed or altered, which can often lead to disease and death. Maintaining their habitat is an extremely important factor in keeping these fish happy and healthy.
  • Immune System Weakness: Cooler water temperatures can cause a loss of vibrancy in color and will potentially weaken their immune system, leaving them at a higher risk for contracting deadly diseases and infections.
  • Habitat Destruction: They are also impacted by human destruction of coral reefs by bleaching or death. Because this species relies so heavily on the reef ecosystem for food and shelter, the decrease in healthy ocean coral will make it difficult for these fish to adapt. Their health is closely tied to the health of coral reef ecosystems.

While this isn’t an disease that impacts Blue Parrotfish, it is worth noting that they have been known to cause ciguatera in humans. Ciguatera is commonly known as fish poisoning sickness. Algae produce a toxin called Gambierdiscus toxicus and the fish absorbs this toxin when it consumes dead and living algae.  When eaten by humans, the toxin can cause fish poisoning and make the person extremely ill with nausea and adverse neurological symptoms. This disease can be fatal as well. While these fish eaten in some countries, they can be deadly when consumed. 

Tank Mates

Blue Parrotfish are peaceful fish, so they can potentially be tank mates with a variety of other peaceful fish. As long as they are placed in a tank of adequate size, they should get along with other fish without issues.

For example, they may potentially be good tank mates with fish such as marine angelfish, clownfish, batfish, butterfly fish, and hogfish. However, due to the fact that Blue Parrotfish grow to a very large size, keeping some of these fish as tank mates in the long term may not make sense.

If small crustaceans such as shrimps and snails are kept in the same tank, the Blue Parrotfish may try to eat them. Small crustaceans aren’t their main food source, but it is a part of their natural diet. Therefore, they should be avoided if you intend to keep these small crustaceans alive.

Overly aggressive species should be avoided as tank mates for Blue Parrotfish as well.

Are Blue Parrotfish Aggressive?

Blue Parrotfish are not typically known to be aggressive. In fact, they are considered to be peaceful fish.

In their natural environment, they foraging in large groups to to deter predators. They spend 80% of their time searching for food in these large groups, similar to herds of cattle. At night, they seek shelter and secrete a mucous that masks their scent, tastes bitter, and makes them harder to find. Males can also intensify their colors to deter any threats.

Within the group, one dominant male usually leads a group of 40 or more females. The male will show aggression to scare away predators from the group. If the male happens to die while defending the group, a female within the group will change its sex to become the new male leader. The female will adopt the bright blue color and protective temperament over the group. They are sequential hermaphrodites, meaning they have the ability to change their sex organs throughout their lives.


Where Can I Find Blue Parrotfish for Sale?

Blue Parrotfish can be bought at local fish stores and online fish stores. While they are difficult to breed in captivity, wild caught specimen are available. However, these aren’t the most popular aquarium fish. Therefore, some fish stores may not have them available in stock. Most of these fish for sale are adults of various sizes, rather than juveniles.

Blue Parrotfish Price

The approximate price of Blue Parrotfish can range from $50 to $300 (USD). The price will range, depending on factors such as their size.

Are Blue Parrotfish Endangered?

The Blue Parrotfish is listed as the Least Concern on the list of endangered species and conservation, according to the International Union for Conservation of Nature. Their total population is unknown, but their population appear to be growing at this time, and they are not rare fish.

Although the species is not considered near endangerment at this time, scientists predict that the Blue Parrotfish will likely get re-classified as Near Threatened in the next ten years. This is mainly due to the destruction and bleaching of coral reefs. Since this species relies so heavily on the reef ecosystem for food and shelter, the decrease in healthy ocean coral will make it difficult for them to adapt.

Other factors that may impact their population is fishing. These fish are eaten in some Caribbean countries, and their scales are used to decorate market items that vendors sell. Due to their bright blue color, their scales are sought after for creating jewelry, lining baskets, and general household craft work.

Do Blue Parrotfish Have Teeth?

The Blue Parrotfish has teeth that are fused together with its top jaw overlapping the lower jaw, creating a beak-shaped facial structure that alludes to its bird-like name. They use this to scrape algae from rocks and coral. In fact, they spend 80 percent of its time looking for food, relying on algae and small organisms found in the sand and coral as its main diet.

They also have teeth in their throats, called pharyngeal apparatus, which they use to grind rocks into the sand while feeding and filtering out tiny organisms. In fact, they are the main contributor to the sand found in ocean reefs and is also responsible for much of the white sand found on the beautiful beaches in the Caribbean.

Are Blue Parrotfish good to eat?

Blue Parrotfish are eaten in some Caribbean countries. However, it’s important to note that they have been known to cause ciguatera, commonly known as fish poisoning sickness, in humans. This disease can be fatal. Therefore, while they are consumed in some places, caution is advised due to the potential health risks. Always ensure that any seafood you consume is safe and prepared properly.

Where do you catch Blue Parrotfish?

The Blue Parrotfish are most often found in the tropical and subtropical waters of the western Atlantic Ocean and Caribbean Sea. They are abundant in the southern region of the Gulf of Mexico and have been reported as far north as Maryland, the U.S.A, and as far south as northern South America. They are also popular in southern Florida regions, including but not limited to the Florida Keys. They enjoy living in coral reefs and shallow coastline waters up to 80 feet in depth and are native to Bermuda, the Bahamas, Jamaica, and Haiti. However, they are not usually found in the northern part of the Gulf of Mexico. They are active during the day.

What are some predators of Blue Parrotfish?

Blue Parrotfish are eaten by larger animals, typically sharks. Also, the secreted mucous envelope deters night predators, especially those who rely on scent for hunting such as moray eels. They secrete a thick “cocoon” of mucus from their mouth before going to sleep, that then covers the animal. It’s thought that this helps to protect them from predators by hiding their scent.

Leave a Comment

Your email address will not be published. Required fields are marked *