Green humphead parrotfish
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Labriformes
Family: Scaridae
Genus: Bolbometopon
J. L. B. Smith, 1956
Species:
B. muricatum
Binomial name
Bolbometopon muricatum
(Valenciennes, 1840)
Synonyms[2]
  • Scarus muricatus Valenciennes, 1840
  • Bolbometopon muricatus (Valenciennes, 1840)
  • Callyodon muricatus (Valenciennes, 1840)

The green humphead parrotfish (Bolbometopon muricatum) is the largest species of parrotfish, growing to lengths of 1.5 m (4.9 ft) and weighing up to 75 kg (165 lb)[citation needed].

It is found on reefs in the Indian and Pacific Oceans, from the Red Sea in the west to Samoa in the east, and from the Yaeyama Islands in the north to the Great Barrier Reef, Australia, in the south.[2]

Other common names include bumphead parrotfish, humphead parrotfish, double-headed parrotfish, buffalo parrotfish, and giant parrotfish.

It is the only species in the monotypic genus Bolbometopon and is the largest herbivorous fish inhabiting coral reefs.[3]

Species description

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.

Reproduction

The green humphead parrotfish, is sexually monochromatic, i.e. there is no initial or terminal phase in the life cycle of the adults.[4] 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.[5] They make use of spawning aggregation sites.

Ritualized headbutting of males at Wake Atoll

Ecology

Newly settled juveniles are found in branching coral habitats (primarily Acropora) in sheltered lagoons.[6] 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.[7]

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,[8] contributing significantly to the bioerosion of reefs. The fish sleeps among corals, in caves and shipwrecks at night, usually in large groups.

Conservation

The large size, slow growth and schooling behavior of this species mean it is susceptible to overfishing.[5] This species is highly sought after by fishermen throughout its range, and it has declined from overharvesting.[9] Spearfishers and netters target large groups as they sleep at night.[10] The species was identified as a Species of Concern by NOAA/NMFS in 2004,[11] meaning that the species is thought to be threatened, but insufficient data are available to justify a listing under the Endangered Species Act.[12][13]

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.[6]

Spearfishing while scuba diving was banned in American Samoa in 2001.[14] The waters surrounding Wake Island, Johnston Atoll, and Palmyra Atoll from the shoreline out to 50 fathoms (91 m) 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.[15]

References

  1. ^ Chan, T.; Sadovy, Y.; Donaldson, T.J. (2012). "Bolbometopon muricatum". IUCN Red List of Threatened Species. 2012: e.T63571A17894276. doi:10.2305/IUCN.UK.2012.RLTS.T63571A17894276.en. Retrieved 19 November 2021.
  2. ^ a b Froese, Rainer; Pauly, Daniel (eds.) (2006). "Bolbometopon muricatum" in FishBase. March 2006 version.
  3. ^ Muñoz, Roldan C.; Zgliczynski, Brian J.; Laughlin, Joseph L.; Teer, Bradford Z. (2012-06-06). Steinke, Dirk (ed.). "Extraordinary Aggressive Behavior from the Giant Coral Reef Fish, Bolbometopon muricatum, in a Remote Marine Reserve". PLOS ONE. 7 (6): e38120. Bibcode:2012PLoSO...738120M. doi:10.1371/journal.pone.0038120. ISSN 1932-6203. PMC 3368943. PMID 22701606.
  4. ^ D.R. Bellwood. "Scaridae" (PDF). FAO. Retrieved 8 February 2020.
  5. ^ a b Taylor, Brett M.; Hamilton, Richard J.; Almany, Glenn R.; Howard Choat, J. (30 July 2018). "The world's largest parrotfish has slow growth and a complex reproductive ecology". Coral Reefs. 37 (4): 1197–1208. Bibcode:2018CorRe..37.1197T. doi:10.1007/s00338-018-1723-9. S2CID 51888896.
  6. ^ a b Hamilton, Richard J.; Almany, Glenn R.; Brown, Christopher J.; Pita, John; Peterson, Nathan A.; Howard Choat, J. (June 2017). "Logging degrades nursery habitat for an iconic coral reef fish". Biological Conservation. 210: 273–280. doi:10.1016/j.biocon.2017.04.024.
  7. ^ Aquatic Life of the World. Marshall Cavendish. 2001. pp. 411–. ISBN 978-0-7614-7177-6.
  8. ^ Kobayashi, D. R.; Friedlander, A. M.; Grimes, C. B.; Nichols, R. S.; Zgliczynski, B. (2011). Bumphead parrotfish (Bolbometopon muricatum) status review (PDF) (Report). NOAA Technical Memorandum. Pacific Islands Fisheries Science Center. NMFS-PIFSC-26.
  9. ^ "Bumphead Parrotfish". fiji.wcs.org. Archived from the original on 2019-03-30. Retrieved 2017-10-22.
  10. ^ Patankar, Vardhan; Wagh, Tanmay; Marathe, Aniruddha (2019-02-28). "Protected areas and benthic characteristics influence the distribution of the Vulnerable bumphead parrotfish Bolbometopon muricatum in the Andaman and Nicobar Islands, India". Oryx. 54 (4): 564–571. doi:10.1017/S0030605318000376. ISSN 0030-6053.
  11. ^ "Species of Concern - Bumphead Parrotfish - fpir.noaa.gov" (PDF).
  12. ^ Fisheries, NOAA. "Proactive Conservation Program: Species of Concern :: NOAA Fisheries". www.nmfs.noaa.gov.
  13. ^ "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)". www.govinfo.gov. November 7, 2012. Retrieved 2019-03-30.
  14. ^ Fishery Management Plan for Coral Reef Ecosystems of the Western Pacific Region: Environmental Impact Statement. 2001. pp. 281–.
  15. ^ Gene S. Helfman (15 July 2007). Fish Conservation: A Guide to Understanding and Restoring Global Aquatic Biodiversity and Fishery Resources. Island Press. pp. 359–. ISBN 978-1-59726-760-1.

External links

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