---
title: "What the sources say about the Green Humphead Parrotfish | AnimalTracks.wiki"
description: "36 claims from the Green Humphead Parrotfish profile, each beside the words of the source that backs it."
image: "https://animaltracks.wiki/images/animals/green-humphead-parrotfish-1.webp"
canonical: "https://animaltracks.wiki/animals/green-humphead-parrotfish/sources/"
---

# What the sources say about the Green Humphead Parrotfish (*Bolbometopon muricatum*)

> 36 claims from the Green Humphead Parrotfish profile, each beside the words of the source that backs it. A "..." marks a cut in a quote and [brackets] an insertion.

Profile: [Green Humphead Parrotfish](https://animaltracks.wiki/animals/green-humphead-parrotfish/)

## Bolbometopon muricatum, Green humphead parrotfish. FishBase.

https://www.fishbase.se/summary/Bolbometopon-muricatum.html

| The page says | The source says |
| :--- | :--- |
| Indo-Pacific coral reefs from the Red Sea and East Africa to Samoa | Indo-Pacific: Red Sea and East Africa to Samoa and the Line Islands (note: stats.habitat) |
| down to 40 m | depth range 0 - 40 m (note: stats.habitat) |
| Algae growing on the reef, live coral and shellfish | feeding on benthic algae, live corals (Ref. 9710 ) and shellfishes (note: stats.diet) |
| It is also the largest of the parrotfishes. | The largest and wariest of the parrotfishes |
| FishBase lists a maximum length of 130 cm and a maximum published weight of 46 kg, with a common length of 70 cm measured without the tail fin. | Max length : 130 cm TL male/unsexed; (Ref. 9710 ); common length : 70.0 cm SL male/unsexed; (Ref. 9793 ); max. published weight: 46.0 kg (Ref. 2334 ) (note: common length is SL (standard length, excludes the caudal fin)) |
| Young fish are brownish to green with rows of whitish spots, then dull grey with white spots, gradually turning uniformly dark green. | Colour of juveniles brownish to green with 5 vertical rows of whitish spots on side, the primary phase is a dull gray with scattered white spots, gradually becoming uniformly dark green |
| It lives across the Indo-Pacific, from the Red Sea and East Africa to Samoa and the Line Islands, north to Wake and south to the Great Barrier Reef | Indo-Pacific: Red Sea and East Africa to Samoa and the Line Islands, north to the Yaeyama and Wake islands, south to the Great Barrier Reef and New Caledonia |
| at depths from the surface to about 40 m | depth range 0 - 40 m |
| It feeds on algae growing on the reef, live coral and shellfish, and sometimes rams its head against coral to help it feed. | feeding on benthic algae, live corals (Ref. 9710 ) and shellfishes (Ref. 58784 ). They sometimes ram their head against corals to facilitate feeding |
| FishBase notes they rest at night in caves and often in shipwrecks. | They ‘sleep’ in caves and often in shipwrecks at night |
| FishBase records a maximum length of 130 cm and a maximum published weight of 46 kg. Its common length is 70 cm, measured without the tail fin. | Max length : 130 cm TL male/unsexed; (Ref. 9710 ); common length : 70.0 cm SL male/unsexed; (Ref. 9793 ); max. published weight: 46.0 kg (Ref. 2334 ) (note: FAQ; common length is 70 cm SL) |

## Sadovy et al. (2025). Bolbometopon muricatum. The IUCN Red List of Threatened Species 2025: e.T63571A264483873.

https://doi.org/10.2305/iucn.uk.2025-2.rlts.t63571a264483873.en

| The page says | The source says |
| :--- | :--- |
| The Red List rates the species Vulnerable. | IUCN Red List category: Vulnerable (VU). (note: IUCN status; Basics: GBIF copy of the Red List, assessed 2024) |

## Muñoz et al. (2012). Extraordinary Aggressive Behavior from the Giant Coral Reef Fish, Bolbometopon muricatum, in a Remote Marine Reserve. PLoS ONE.

https://doi.org/10.1371/journal.pone.0038120

| The page says | The source says |
| :--- | :--- |
| The biggest herbivorous fish on coral reefs | Bolbometopon is the largest herbivorous fish on coral reefs (note: tagline) |
| whose males settle rivalries with headbutts | violent headbutting contests by the world’s largest parrotfish (note: tagline) |
| Males headbutt rivals with loud, jarring impacts | we heard loud jarring sounds and confirmed they arose from violent impacts between males engaged in repeated, ritualized headbutting behavior (note: stats.superpower) |
| divers heard loud, jarring sounds and traced them to male green humphead parrotfish | we heard loud jarring sounds and confirmed they arose from violent impacts between males engaged in repeated, ritualized headbutting behavior |
| In the early morning on the outer reef of Wake Atoll, in the western Pacific | Impact sounds and headbutting were documented on multiple occasions (five and two separate days, respectively) from approximately 0630–0815 h (note: Study sites were on the outer fore reef (Methods): 'We chose study sites along the outer fore reef') |
| using their tail fins to slam their forehead humps together | males utilized their caudal fins to rapidly collide with their cephalic humps |
| Then they swam fast in a half circle, each trying to bite the other's back and flank, swam apart and turned face to face for another collision. | immediately followed by fast swimming in a semicircle where each fish tried to bite the back and flank of its opponent ... Following circling, fish swam apart in opposite directions and then turned again face to face to initiate additional collisions |
| In one bout caught on video, four charges ended when the subordinate male fled. | consisting of four, successive charges between two males. The first three resulted in impact ... and the fourth charge resulted in the subordinate male fleeing the contest |
| The researchers knew of no earlier scientific record of ritualized headbutting in any marine fish. | to our knowledge, no scientific documentation of ritualized headbutting exists for marine fishes (note: 'To our knowledge' in source) |
| This is the largest herbivorous fish on coral reefs. | Bolbometopon is the largest herbivorous fish on coral reefs |
| It grows slowly, starts breeding late and replaces its numbers slowly | It is slow-growing and long-lived with delayed reproduction and low replenishment rates |
| as a result even moderate fishing has led to severe declines in the size and numbers of fish across much of its range | As a result, even moderate levels of exploitation have led to severe declines in size-structure and abundance of populations throughout much of its range |
| Night spearfishing grew with underwater flashlights in the 1970s, and in the western Solomon Islands it led to the disappearance of sleeping groups that had lasted for generations. | night spearfishing increased with the advent of underwater flashlights in the 1970’s, and in the western Solomon Islands led to overexploitation and the disappearance of sleeping aggregations that had persisted and supported subsistence fishing for generations |
| Overfishing has made it shy of people: it has a name as the wariest parrotfish, and divers struggle to get close to one in most places. | Overfishing has led to a general avoidance of humans; it is known as the wariest of parrotfishes and in most locations individuals are difficult to approach underwater |
| At Wake Atoll, males clash in repeated, ritualized headbutting contests, and researchers in the water heard the collisions as loud, jarring sounds. | we heard loud jarring sounds and confirmed they arose from violent impacts between males engaged in repeated, ritualized headbutting behavior (note: FAQ) |
| Male green humphead parrotfish charge and slam their forehead humps together, and divers heard the collisions as loud, jarring sounds | we heard loud jarring sounds and confirmed they arose from violent impacts between males engaged in repeated, ritualized headbutting behavior (note: vibe.reason) |

## Muñoz et al. (2014). Spawning aggregation behavior and reproductive ecology of the giant bumphead parrotfish, Bolbometopon muricatum, in a remote marine reserve. PeerJ.

https://doi.org/10.7717/peerj.681

| The page says | The source says |
| :--- | :--- |
| On Australia's Great Barrier Reef, one of these fish can wear away over 5 tons of reef rock in a year. | On the GBR, Bolbometopon play an important ecological role where individuals are capable of bio-eroding over 5 tons of reef carbonate each year (note: Reef carbonate = reef rock; GBR abbreviation expanded) |
| Females can live to 40 years, and it is the longest-lived parrotfish. | Bolbometopon is the longest-lived parrotfish (females capable of reaching 40 years, Hamilton & Choat, 2012 ) (note: Source cites Hamilton & Choat 2012 for the figure) |
| Green humphead parrotfish often sleep and feed in big groups in shallow water | often sleeping and feeding in large groups in shallow water (1–15 m deep) |
| On the Great Barrier Reef, schools of 30 to 50 are seen regularly. | schools of 30–50 individuals can be observed regularly |
| At Wake Atoll the mating system was a lek: males arrived early and defended small territories, apparently to attract females, who came later in big schools. | The mating system was lek-based, characterized by early male arrival at the spawning site followed by vigorous defense (including head-butting between large males) of small territories. These territories were apparently used to attract females that arrived later in large schools |
| There, the fish spawned on mornings near the full moon and the last quarter moon. | spawning activities in the morning around the full and last quarter moon |
| No parrotfish lives longer: a female can reach 40 years. | Bolbometopon is the longest-lived parrotfish (females capable of reaching 40 years, Hamilton & Choat, 2012 ) (note: FAQ) |
| Wake Atoll, in the western Pacific | Wake Atoll, a remote and protected coral atoll in the west Pacific |