Green humphead parrotfish

Green humphead parrotfish Bolbometopon muricatum
Conservation status
Vulnerable (IUCN 3.1)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
Order:	Perciformes
Family:	Scaridae
Genus:	Bolbometopon J. L. B. Smith, 1956
Species:	B. muricatum
Binomial name
Bolbometopon muricatum (Valenciennes, 1840)

The green humphead parrotfish, Bolbometopon muricatum, is the largest species of parrotfish growing to lengths of 1.3 metres (4.3 ft) and weighing up to 46 kilograms (100 lb).^[1] 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.

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

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. Adults develop a bulbous forehead and their teeth plates are exposed (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 (> 75) on seaward and clear outer lagoon reefs.

Reproduction

They spawn pelagically near the outer reef slope or near promontories, gutters, or channel mouths during a lunar cycle and they utilize spawning aggregations sites.

Ecology

Juvenile green humphead parrotfish are found in lagoons, often in seagrass beds, and adults are found in clear outer lagoon and seaward reefs up to depths of at least 30 m. They are usually found in small groups, and they feed on benthic algae and live corals. They may ram their head against corals to facilitate feeding. Each adult fish ingests over 5 tons of structural reef carbonates per year, contributing significantly to the bioerosion of reefs. They sleep in caves and shipwrecks at night.

Conservation

They are highly desired throughout their range and have declined from overharvesting or habitat degradation and destruction in most places. They sleep in large groups, thus rendering them highly vulnerable to exploitation by spearfishers and netters at night. The green humphead parrotfish is a U.S. National Marine Fisheries Service Species of Concern, where it is listed as the bumphead parrotfish. Species of Concern are those species about which the U.S. Government’s National Oceanic and Atmospheric Administration, National Marine Fisheries Service has some concerns regarding status and threats, but for which insufficient information is available to indicate a need to list the species under the U.S. Endangered Species Act (ESA).

Spearfishing while on SCUBA was banned in American Samoa in 2001, but enforcement is limited. The waters surrounding Wake Island, Johnston Atoll, and Palmyra Atoll from the shoreline out to 50 fathoms (90 m) are protected as a low-use marine protected area, which means that any person of the United States fishing for, taking, or retaining them must have a special permit. Also, they may not be taken by means of spearfishing with SCUBA gear from 6 p.m. to 6 a.m. in the U.S. Exclusive Economic Zone waters around Wake Island, Johnston Atoll, or Palmyra Atoll. Palau’s population of the bumphead parrotfish is now protected by an export ban and a national minimum size restriction of 25 inches (640 mm).

See also

• Humphead wrasse, Cheilinus undulatus

References

1. ^ Froese, Rainer, and Daniel Pauly, eds. (2006). "Bolbometopon muricatum" in FishBase. March 2006 version.

• "Bolbometopon muricatum". Integrated Taxonomic Information System. http://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=170884. Retrieved 11 March 2006. 

External links

• Green humphead parrotfish at the Encyclopedia of Life