Large parrotfish uniformly turquoise‑blue as adults, with juveniles showing a yellow spot on the crown that fades with age. Body laterally compressed; terminal mouth forms a robust, fused “beak” of dentary plates used to scrape algae and epilithic organisms. Pharyngeal teeth triturate ingested substrate into fine sand. Dorsal fin continuous with 9 spines and 10 soft rays; caudal fin lunate in adults. Typical length 30–75 cm, maximum 1.2 m; mass to ~9 kg. Sexual dimorphism subtle—males slightly larger and may develop a cranial hump.
Yes — males attain larger size and may show cranial hump; coloration otherwise uniform blue in both sexes.
Total length 30–75 cm (max 120 cm)
≈ 3–9 kg
Up to 7 yr in the wild
Data deficient
Data deficient
c. 2–3 yr / ≥ 30 cm TL
Spawning aggregations peak May–August in W. Caribbean
Eggs hatch ≈ 25 h after release
Large parrotfish uniformly turquoise‑blue as adults, with juveniles showing a yellow spot on the crown that fades with age. Body laterally compressed; terminal mouth forms a robust, fused “beak” of dentary plates used to scrape algae and epilithic organisms. Pharyngeal teeth triturate ingested substrate into fine sand. Dorsal fin continuous with 9 spines and 10 soft rays; caudal fin lunate in adults. Typical length 30–75 cm, maximum 1.2 m; mass to ~9 kg. Sexual dimorphism subtle—males slightly larger and may develop a cranial hump.
Diurnal grazer scraping epilithic algae and detritus; bioeroding beak converts carbonate substrate to sediment, contributing to beach sand formation.
Activity pattern: strictly diurnal; spends up to 80 % of daylight hours grazing.
Group size: juveniles mostly solitary; adults form mobile “grazing herds” of 10 – 50 fish across reef flats.
Mating system: protogynous hermaphrodite; dominant terminal males oversee loose harems and pair‑spawn within large dawn aggregations on outer‑reef slopes (May – Aug peak).
Territoriality: generally non‑territorial while feeding; males defend small courtship arenas (“lek” patches) during breeding season.
Communication: colour flashes and lateral displays signal dominance; at night individuals secrete a thin mucous envelope that may mask scent from nocturnal predators.
A single blue parrotfish can create > 90 kg of sand per year by grinding reef rock in its pharyngeal mill.
Adults are one of the few Caribbean fishes that remain solid blue throughout life, aiding instant identification. Wikipedia
Forms daytime “grazing herds” of dozens that plough reef flats, flushing prey for trailing wrasses and jacks.
Exhibits site fidelity but undertakes dawn and dusk spawning runs to outer‑reef drop‑offs where eggs drift pelagically.
Their beaks are so hard that indigenous Taíno peoples reputedly used the jawplates as natural scrapers and chisels.
