Quoy's Parrotfish (Scarus Quoyi) saltwater aquarium fish portrait

Quoy's Parrotfish, also traded as the Green Blotch or Greenblotch Parrotfish, carries a rainbow-like blend of green, blue, purple, and orange to pink tones, with mature males distinguished by a bright green cheek patch. The fused, beak-like dentition typical of parrotfishes is clearly visible and functional, used to scrape algal films from hard surfaces. The species ranges widely through the Indo-West Pacific, from India east to Vanuatu, north to the Ryukyu Islands and south to New Caledonia, including Palau, where it occupies coral-rich outer channels, seaward reefs, and intertidal reef flats, usually alone or in small grazing groups.

Adult housing should be built around open swimming lanes paired with heavily established rockwork that supplies both grazing surfaces and nighttime shelter. A 50-gallon aquarium is the functional minimum, though this is an active, strong-swimming grazer and the additional length and volume of a larger system will always serve it better. Maturity in the aquascape matters, since a sterile, freshly cycled tank will not supply the constant film algae this fish expects to find.

Waste output is heavy relative to the fish's size, so robust mechanical and biological filtration, strong oxygenation, and disciplined water changes are not optional. Vigorous circulation across rockwork helps both gas exchange and nutrient export. This is a demanding species to maintain long term, and even specimens that appear to be settled and feeding well can decline unexpectedly, so it belongs with aquarists prepared to commit to sustained, careful husbandry.

In the wild this parrotfish works continuously over reef rock and coral surfaces, scraping algal films with its beak and incidentally ingesting fragments of dead coral rock, which it later expels as fine sand. That grazing pattern means near-constant food intake rather than discrete meals, and captive feeding should be built to approximate it. Algae-based items form the core of the diet: dried marine algae sheets, nori, spirulina-based flake, and herbivore pellet formulas.

Offer small amounts several times daily, and secure sheet algae to a clip on the rockwork so the fish can graze rather than chase drifting pieces. Modest portions of meaty frozen foods such as mysis and brine shrimp round out the diet and help maintain condition. Heavy dietary supplementation is important given the volume this grazer consumes, and filtration capacity should be matched to the resulting feeding load.

Dried Marine Algae Sheets Nori Spirulina Flake Herbivore Pellets Frozen Mysis Shrimp Frozen Brine Shrimp
Quoy's Parrotfish is a peaceful, endlessly busy fish that spends most of daylight hours cruising over rockwork in search of algae. Its size, speed, and grazing persistence can make it a dominant presence in a community even without hostility toward other species. At night it retires into the rockwork, and it may enclose itself in a mucous cocoon while resting. Territorial friction is most likely with its own kind, particularly between two males, so keep only one specimen per system.

Suitable companions are peaceful to moderately robust marine fishes that will neither bully this parrotfish nor contest grazing surfaces too aggressively. Hobbyist accounts report success alongside tangs, rabbitfish, a puffer, and triggerfish in large fish-only-with-live-rock systems. It is not a dedicated coral feeder and is generally reported to leave shrimp and starfish alone, but the beak can scrape hard surfaces, dislodge unsecured frags, and damage or consume SPS corals while grazing, which is why it is not considered reef safe. Keep it in a fish-only or live-rock display rather than a coral-focused reef.

FAQ

Frequently Asked Questions

About the Quoy's Parrotfish

  • How large an aquarium does Quoy's Parrotfish need as an adult?
    A 50-gallon aquarium is the minimum for this 6-inch fish, though larger systems with long open swimming lanes suit its constant activity far better. Extensive mature rockwork for grazing and shelter is as important as raw volume.
  • Can Quoy's Parrotfish be kept in a coral reef aquarium?
    No. Although its diet is algae-based and it generally ignores shrimp and starfish, its beak can scrape hard surfaces, unsettle loose frags, and damage or consume SPS corals while grazing.
  • Why is this parrotfish considered a difficult species to keep?
    It grazes nearly constantly and requires heavy algae-based feeding, and its waste output demands strong filtration and oxygenation. Specimens that feed well can still decline unexpectedly, so sustained attention to water quality and nutrition is essential.