green humphead parrotfish

File:Sexual dimorphism in Bolbometopon muricatum.png

Unlike wrasses, it has a vertical head profile, and unlike other parrotfishes, it is uniformly covered with scales except for the leading edge of the head, which is often light green to pink. Primary phase colouration is a dull gray with scattered white spots, gradually becoming uniformly dark green. This species does not display sex-associated patterns of color change. The adult develops a bulbous forehead and the teeth plates are exposed, being only partly covered by lips. The species is slow-growing and long-lived (up to 40 years), with delayed reproduction and low replenishment rates.

This species is gregarious and usually occurs in small aggregations, but group size can be quite large on seaward and clear outer lagoon reefs, exceeding 75 individuals.

The green humphead parrotfish, is sexually monochromatic, i.e. there is no initial or terminal phase in the life cycle of the adults.{{cite web | url = http://www.fao.org/3/y0870e/y0870e11.pdf | author = D.R. Bellwood | title = Scaridae | access-date = 8 February 2020 | publisher = FAO}} The fish spawn pelagically near the outer reef slope or near promontories, gutters, or channel mouths during a lunar cycle, usually spawning just prior to the new moon.{{cite journal |last1=Taylor |first1=Brett M. |last2=Hamilton |first2=Richard J. |last3=Almany |first3=Glenn R. |last4=Howard Choat |first4=J. |title=The world's largest parrotfish has slow growth and a complex reproductive ecology |journal=Coral Reefs |date=30 July 2018 |volume=37 |issue=4 |pages=1197–1208 |doi=10.1007/s00338-018-1723-9 |bibcode=2018CorRe..37.1197T |s2cid=51888896 }} They make use of spawning aggregation sites.

File:Extraordinary-Aggressive-Behavior-from-the-Giant-Coral-Reef-Fish-Bolbometopon-muricatum-in-a-Remote-pone.0038120.s001.ogv of males at Wake Atoll]]

Newly settled juveniles are found in branching coral habitats (primarily Acropora) in sheltered lagoons.{{cite journal |last1=Hamilton |first1=Richard J. |last2=Almany |first2=Glenn R. |last3=Brown |first3=Christopher J. |last4=Pita |first4=John |last5=Peterson |first5=Nathan A. |last6=Howard Choat |first6=J. |title=Logging degrades nursery habitat for an iconic coral reef fish |journal=Biological Conservation |date=June 2017 |volume=210 |pages=273–280 |doi=10.1016/j.biocon.2017.04.024 |bibcode=2017BCons.210..273H }} Small juveniles (<50mm) are often associated with Damselfish. Larger juvenile green humphead parrotfish are found in lagoons, often in seagrass beds, and the adults are found in clear outer lagoons and seaward reefs up to a depth of 30 m. They feed on benthic algae and live corals.{{cite book|title=Aquatic Life of the World|url=https://books.google.com/books?id=T2qZHTpbiowC&pg=PA411|year=2001|publisher=Marshall Cavendish|isbn=978-0-7614-7177-6|pages=411–}}

Adult green humphead parrotfish may ram its head against corals to facilitate feeding. Each adult fish ingests over five tons of structural reef carbonates per year,{{cite report|last1=Kobayashi|first1=D. R.|last2=Friedlander|first2=A. M.|last3=Grimes|first3=C. B.|last4=Nichols|first4=R. S.|last5=Zgliczynski|first5=B.|year=2011|title=Bumphead parrotfish (Bolbometopon muricatum) status review|series=NOAA Technical Memorandum|id=NMFS-PIFSC-26|publisher=Pacific Islands Fisheries Science Center|url=https://www.cio.noaa.gov/services_programs/prplans/pdfs/ID158_Bumphead_Parrotfish_Final_Product.pdf}} contributing significantly to the bioerosion of reefs. The fish sleeps among corals, in caves and shipwrecks at night, usually in large groups.

The large size, slow growth and schooling behavior of this species mean it is susceptible to overfishing. This species is highly sought after by fishermen throughout its range, and it has declined from overharvesting.{{cite web|url=https://fiji.wcs.org/Wildlife/Bumphead-Parrotfish.aspx|title=Bumphead Parrotfish|website=fiji.wcs.org|access-date=2017-10-22|archive-date=2019-03-30|archive-url=https://web.archive.org/web/20190330154648/https://fiji.wcs.org/Wildlife/Bumphead-Parrotfish.aspx|url-status=dead}} Spearfishers and netters target large groups as they sleep at night.{{Cite journal|last1=Patankar|first1=Vardhan|last2=Wagh|first2=Tanmay|last3=Marathe|first3=Aniruddha|date=2019-02-28|title=Protected areas and benthic characteristics influence the distribution of the Vulnerable bumphead parrotfish Bolbometopon muricatum in the Andaman and Nicobar Islands, India|journal=Oryx|volume=54|issue=4|language=en|pages=564–571|doi=10.1017/S0030605318000376|issn=0030-6053|doi-access=free}} The species was identified as a Species of Concern by NOAA/NMFS in 2004,{{Cite web|url=https://www.fpir.noaa.gov/Library/PRD/SOC/Revised%20fact%20sheets_2010/bumphead%20parrotfish%202%20pg_new.pdf|title=Species of Concern - Bumphead Parrotfish - fpir.noaa.gov|date=17 April 2024 }} meaning that the species is thought to be threatened, but insufficient data are available to justify a listing under the Endangered Species Act.{{cite web|url=http://www.nmfs.noaa.gov/pr/species/concern/|title=Proactive Conservation Program: Species of Concern :: NOAA Fisheries|first=NOAA|last=Fisheries|website=www.nmfs.noaa.gov|date=21 December 2023 }}{{Cite web|url=https://www.govinfo.gov/app/details/FR-2012-11-07/2012-27244/summary|title=77 FR 66799 - Endangered and Threatened Wildlife and Plants: Notice of 12-Month Finding on a Petition To List the Bumphead Parrotfish as Threatened or Endangered Under the Endangered Species Act (ESA)|date=November 7, 2012|website=www.govinfo.gov|access-date=2019-03-30}}

Habitat degradation and destruction has accelerated the decline. Juvenile habitats are susceptible to being degraded by poor water quality, such as run-off of sediments from logging.

Spearfishing while scuba diving was banned in American Samoa in 2001.{{cite book|title=Fishery Management Plan for Coral Reef Ecosystems of the Western Pacific Region: Environmental Impact Statement|url=https://books.google.com/books?id=XOc3AQAAMAAJ&pg=PA281|year=2001|pages=281–}} The waters surrounding Wake Island, Johnston Atoll, and Palmyra Atoll from the shoreline out to {{convert|50|fathom|m|abbr=on}} are protected as low-use marine protected areas, which means any person of the United States fishing for, taking, or retaining this fish must have a special permit. Also, it may not be taken by means of spearfishing with SCUBA gear from 6 pm to 6 am in the US Exclusive Economic Zone waters around these territories. The population of the fish in Palau is now protected by an export ban.{{cite book|author=Gene S. Helfman|title=Fish Conservation: A Guide to Understanding and Restoring Global Aquatic Biodiversity and Fishery Resources|url=https://books.google.com/books?id=eGGqGYEQXDkC&pg=PA359|date=15 July 2007|publisher=Island Press|isbn=978-1-59726-760-1|pages=359–}}

{{Reflist}}

{{Wikispecies|Bolbometopon muricatum}}

{{Commons category|Bolbometopon muricatum}}

• {{ITIS |id=170884 |taxon=Bolbometopon muricatum |accessdate=11 March 2006}}
• {{SealifePhotos|219074}}

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Category:Labridae

Category:Articles containing video clips

Category:Taxa named by Achille Valenciennes

Category:Fish described in 1840

Category:Fish of Palau