Bolbometopon muricatum—the bumphead parrotfish—is the world’s largest parrotfish (family Scaridae). Adults have a distinctive forehead “bump” and feed by scraping and biting coral substratesto access algal films and endolithic organisms, acting as key bioeroders and sand producers on coral reefs.
Ecology & Biology
Diet: algal turf and organisms within/among coral frameworks; feeding often involves biting coral skeletons.
Behaviour: commonly schooling by day (dozens to hundreds) on outer reef slopes/crests; communal resting at night.
Reproduction: forms seasonal spawning aggregations with pelagic broadcast spawning; juveniles use more sheltered reef/seagrass habitats.
Life history: slow‑growing, late‑maturing and long‑lived; predictable habitats and aggregations increase fishing vulnerability.
Identification
Very large body with a massive cephalic hump; hump is used in head‑butting displays within schools.
Robust beak‑like jaws (parrotfish rostrum); overall grey‑green to bluish‑grey; juveniles show pale spots/bands.
Caudal fin truncate to slightly emarginate; coarse scales; modest sexual dichromatism.
Size & Longevity
Length: typically 80–120 cm, up to about ~130 cm or more.
Weight: can reach tens of kilograms in large adults.
Life: on the order of multiple decades (region‑dependent).
Range & Habitat
Indo‑Pacific tropical reefs from the Red Sea eastward to Micronesia/Papua New Guinea/the Great Barrier Reef, favouringouter reef slopes, crests and fore‑reefs in shallow to mid‑shallow water.
Conservation & Threats
Threats: night spearfishing, targeting of spawning aggregations, overfishing and habitat degradation.
Measures: aggregation closures, size/bag limits, marine protected areas and community‑based monitoring/management.
IUCN: widely cited as Vulnerable (VU) (check latest assessment for updates).
