Green Parrotfish

Green Parrotfish: The Giant Algae Grazer of the Reef

The Green Parrotfish (Chlorurus bleekeri) is a large, highly active, and important herbivore of the reef ecosystem. Though sometimes referred to by its older scientific name, Scarus bleekeri, it is correctly classified as part of the genus Chlorurus within the Parrotfish family Scaridae. Like many Parrotfish, it exhibits dramatic sexual color changes, transitioning from the subdued Initial Phase (IP) to the brilliant Terminal Phase (TP) male.

The Terminal Phase male is the most striking, characterized by its dominant blue-green body coloration, scales edged with pink, and a distinctive **green-bordered white or cream patch** on the cheek. This vibrant pattern is what inspires the name Green Parrotfish. The Initial Phase (females and non-terminal males) is a much less flashy blend of dark brown or purplish with broad, pale horizontal bars.

Hailing from the Indo-Pacific, this species can reach an impressive size, growing up to 19 inches (49 cm). Its large size and continuous grazing lifestyle mean it is suitable only for extremely large, well-established public or custom home aquariums (a minimum size of 500+ gallons is recommended). They are constant grazers and their demanding dietary needs and bioload require expert-level husbandry.

---

Diet & Compatibility:

• Diet: As an adult, the Green Parrotfish is a dedicated Herbivore (scraper). Its specialized beak-like dental plates are used to constantly scrape filamentous algae and turf algae from rock and dead coral surfaces. They require an enormous supply of natural algae, which must be supplemented with liberal amounts of dried **Nori/seaweed sheets** (offered multiple times daily), along with high-quality, vegetable-based marine pellets and flakes.
• Reef Compatibility: It is Reef Safe With Extreme Caution (Expert Only). While their primary diet is algae, their constant and powerful scraping action means large Parrotfish will damage or inadvertently consume stony corals (especially SPS) while targeting the algae growing on or beneath the coral skeleton. They are generally safe with most motile ornamental invertebrates.
• Temperament: It is Semi-Aggressive / Boisterous. It is a powerful, active swimmer that requires spacious quarters and should only be housed with large, robust tankmates. It may show aggression toward conspecifics or similar-looking wrasses, making it best kept singly unless the system is massive.
• Special Care: This fish produces a very high bioload. Maintaining pristine water quality is non-negotiable and requires industrial-strength protein skimming, ample live rock, and a rigorous schedule of large water changes.

---

Quick Facts

• Scientific Name: Chlorurus bleekeri (Syn. Scarus bleekeri)
• Primary Common Name: Green Parrotfish
• Other Common Names: Bleeker's Parrotfish, Bleeker's Scarus
• Origin: Indo-Pacific (Widespread)
• Max Size: Up to 19 inches (49 cm)
• Temperament: Semi-Aggressive / Boisterous
• Diet: Herbivore (Constant grazer of turf/filamentous algae)
• Minimum Tank Size: 500+ Gallons (Expert-only system)
• Reef Compatibility: With Extreme Caution (May damage coral)