Green humphead parrotfish
Encyclopedia
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 (101.4 lb). It is found on reef
s in the Indian
and Pacific Ocean
s, 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.
s, it has a vertical head profile, and unlike other parrotfishes, it is uniformly covered with scale
s 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.
s. 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.
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 (91.4 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 (635 mm).
Parrotfish
Parrotfishes are a group of fishes that traditionally had been considered a family , but now often are considered a subfamily of the wrasses. They are found in relatively shallow tropical and subtropical oceans throughout the world, but with the largest species richness in the Indo-Pacific...
growing to lengths of 1.3 metres (4.3 ft) and weighing up to 46 kilograms (101.4 lb). It is found on reef
Reef
In nautical terminology, a reef is a rock, sandbar, or other feature lying beneath the surface of the water ....
s in the Indian
Indian Ocean
The Indian Ocean is the third largest of the world's oceanic divisions, covering approximately 20% of the water on the Earth's surface. It is bounded on the north by the Indian Subcontinent and Arabian Peninsula ; on the west by eastern Africa; on the east by Indochina, the Sunda Islands, and...
and Pacific Ocean
Pacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...
s, from the Red Sea
Red Sea
The Red Sea is a seawater inlet of the Indian Ocean, lying between Africa and Asia. The connection to the ocean is in the south through the Bab el Mandeb strait and the Gulf of Aden. In the north, there is the Sinai Peninsula, the Gulf of Aqaba, and the Gulf of Suez...
in the west to Samoa
Samoa
Samoa , officially the Independent State of Samoa, formerly known as Western Samoa is a country encompassing the western part of the Samoan Islands in the South Pacific Ocean. It became independent from New Zealand in 1962. The two main islands of Samoa are Upolu and one of the biggest islands in...
in the east, and from the Yaeyama Islands
Yaeyama Islands
The Yaeyama Islands are a group of islands in Okinawa Prefecture, Japan.The isles are the remotest part of Japan from the main islands and contains Japan's most southern and most western inhabited islands.The islands form the southern part of the volcanic Nansei Islands...
in the north to the Great Barrier Reef
Great Barrier Reef
The Great Barrier Reef is the world'slargest reef system composed of over 2,900 individual reefs and 900 islands stretching for over 2,600 kilometres over an area of approximately...
, Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
in the south.
Other common names include bumphead parrotfish, humphead parrotfish, double-headed parrotfish, buffalo parrotfish and giant parrotfish.
Species description
Unlike wrasseWrasse
The wrasses are a family, Labridae, of marine fish, many of which are brightly colored. The family is large and diverse, with over 600 species in 82 genera, which are divided into nine subgroups or tribes....
s, it has a vertical head profile, and unlike other parrotfishes, it is uniformly covered with scale
Scale (zoology)
In most biological nomenclature, a scale is a small rigid plate that grows out of an animal's skin to provide protection. In lepidopteran species, scales are plates on the surface of the insect wing, and provide coloration...
s 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
Group size measures
Many animals, including humans, tend to live in groups, herds, flocks, bands, packs, shoals, or colonies of conspecific individuals. The size of these groups, as expressed by the number of participant individuals, is an important aspect of their social environment...
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 coralCoral
Corals are marine animals in class Anthozoa of phylum Cnidaria typically living in compact colonies of many identical individual "polyps". The group includes the important reef builders that inhabit tropical oceans and secrete calcium carbonate to form a hard skeleton.A coral "head" is a colony of...
s. 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
Bioerosion
Bioerosion describes the erosion of hard ocean substrates – and less often terrestrial substrates – by living organisms. Marine bioerosion can be caused by mollusks, polychaete worms, phoronids, sponges, crustaceans, echinoids, and fish; it can occur on coastlines, on coral reefs, and...
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
Spearfishing
Spearfishing is an ancient method of fishing that has been used throughout the world for millennia. Early civilizations were familiar with the custom of spearing fish from rivers and streams using sharpened sticks....
while on SCUBA
Scuba diving
Scuba diving is a form of underwater diving in which a diver uses a scuba set to breathe underwater....
was banned in American Samoa
American Samoa
American Samoa is an unincorporated territory of the United States located in the South Pacific Ocean, southeast of the sovereign state of Samoa...
in 2001, but enforcement is limited. The waters surrounding Wake Island
Wake Island
Wake Island is a coral atoll having a coastline of in the North Pacific Ocean, located about two-thirds of the way from Honolulu west to Guam east. It is an unorganized, unincorporated territory of the United States, administered by the Office of Insular Affairs, U.S. Department of the Interior...
, Johnston Atoll
Johnston Atoll
Johnston Atoll is a atoll in the North Pacific Ocean about west of Hawaii. There are four islands located on the coral reef platform, two natural islands, Johnston Island and Sand Island, which have been expanded by coral dredging, as well as North Island and East Island , an additional two...
, and Palmyra Atoll
Palmyra Atoll
Palmyra Atoll is an essentially unoccupied equatorial Northern Pacific atoll administered as an unorganized incorporated territory by the United States federal government...
from the shoreline out to 50 fathoms (91.4 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 (635 mm).