Difference between revisions of "Halibut" - New World Encyclopedia

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{{Taxobox
 
{{Taxobox
 
| name = Halibut
 
| name = Halibut
 
| image = Pacific Halibut.JPG
 
| image = Pacific Halibut.JPG
 
| image_width  = 240px
 
| image_width  = 240px
| image_caption = Pacific halibut (''H. stenolepis''). <br>Halibut tend to be a mottled brown on their upward-facing side and white on their downside
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| image_caption = Pacific halibut ''(H. stenolepis)''. <br/>Halibut tend to be a mottled brown on their upward-facing side and white on their downside
 
| regnum = [[Animalia]]  
 
| regnum = [[Animalia]]  
 
| phylum = [[Chordata]]  
 
| phylum = [[Chordata]]  
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| familia = [[Pleuronectidae]]  
 
| familia = [[Pleuronectidae]]  
 
| genus = ''[[Hippoglossus]]''
 
| genus = ''[[Hippoglossus]]''
| subdivision_ranks = [[Species]]<br>
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| subdivision_ranks = [[Species]]<br/>
 
| subdivision =
 
| subdivision =
''H. hippoglossus'' (Atlantic halibut)<br>
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''H. hippoglossus'' (Atlantic halibut)<br/>
 
''H. stenolepis'' (Pacific halibut)
 
''H. stenolepis'' (Pacific halibut)
 
}}
 
}}
  
'''Halibut''' is the common name for any flatfish (order Pleuronectiformes) belonging to the genus ''Hippoglossus'' from the family of right-eye [[flounder]]s (Pleuronectidae), of which there are two extant species, the Atlantic halibut (''H. hippoglossus'') and the Pacific halibut (''H. stenolepis''). Demersal fish, that live near the bottom of the ocean as adults, halibut are characterized by having both eyes on their dark or upper side and somewhat more elongated bodies than other flatfish, with a somewhat lunate caudal fin. They also exhibit large size, being among the largest teleost (bony) fish in the world. They also are strong swimmers and can migrate long distances. The common name halibut also is used for some other species of flatfish.
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'''Halibut''' is the common name for any flatfish (order Pleuronectiformes) belonging to the genus ''Hippoglossus'' from the family of right-eye [[flounder]]s (Pleuronectidae), of which there are two extant [[species]], the Atlantic halibut ''(H. hippoglossus)'' and the Pacific halibut ''(H. stenolepis)''. Demersal fish, that live near the bottom of the ocean as adults, halibut are characterized by having both eyes on their dark or upper side and somewhat more elongated bodies than other flatfish, with a somewhat lunate caudal fin. They also exhibit large size, being among the largest [[teleost]] (bony) [[fish]] in the world. They also are strong swimmers and can migrate long distances. The common name halibut also is used for some other species of flatfish.
  
 
The Atlantic halibut is native to the temperate waters of the northern [[Atlantic Ocean|Atlantic]], from [[Labrador]] and [[Greenland]] to [[Iceland]], the [[Barents Sea]] and as far south as the [[Bay of Biscay]]. The Pacific halibut is found on the continental shelf of the North Pacific Ocean and Bering sea.
 
The Atlantic halibut is native to the temperate waters of the northern [[Atlantic Ocean|Atlantic]], from [[Labrador]] and [[Greenland]] to [[Iceland]], the [[Barents Sea]] and as far south as the [[Bay of Biscay]]. The Pacific halibut is found on the continental shelf of the North Pacific Ocean and Bering sea.
  
very pouplar food  
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Halibut is a very popular food, with lean, white, sweet-flavored flesh with few bones and high nutritional value. As a result, a lucrative halibut fishery has developed, and it is also popular in sport fishing. Halibut also is important [[ecology|ecologically]] as an integral part of marine [[food chain]]s. An adult female can produce millions of eggs, with the [[egg (biology)|eggs]] and [[larva]] providing food for numerous marine animals. And while the adult halibut is so large that it is near the top of the food chain, it too may be preyed upon by [[sea lion]]s, [[orca]]s, [[shark]]s, and [[seal]]s. On the other hand, the strong-swimming halibut is able to capture and feed upon a wide variety of [[fish]], [[crustacean]]s, and [[mollusk]]s.
  
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Despite these ecological, commercial, recreational, and nutritional values, overfishing of the Atlantic halibut has resulted in being rated as an [[endangered species]], with a high risk of [[extinction]] in the wild. A contributing factor is that the halibut does not reach sexual maturity until roughly eight years of age. The Pacific halibut, however, continues to have healthy populations, and remains a lucrative commercial fishery.
  
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==Overview and description==
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[[Image:Alaska 2007 071.jpg|256px|thumb||right|Halibut caught off the coast of [[Raspberry Island, Alaska]]. The two fish being held up are 70 to 80 pounds.]]
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Halibut are a type of "flatfish." Flatfish are an [[order (biology)|order]] ''(Pleuronectiformes)'' of [[ray-finned fish]] (Actinopterygii,). (Flatfish sometimes are classified as a suborder of the order [[Perciformes]].) Flatfish are a very distinctive group in that the adults are not [[Symmetry (biology)#Bilateral symmetry|bilaterally symmetrical]], the only fish with such asymmetry and the only [[vertebrate]]s that deviate so radially from the bilaterally symmetrical body plan (Grzimek et al. 2004). The young flatfish are bilaterally symmetrical and swim upright as with other fish, but early in development one of the eyes migrates to the other side of the cranium, across the top of the skull, and positions itself adjacent to the eye on the other side (Nelson 1994). The fish then swims with the two eyes on the upper side and lower side is blind. The metamorphosis also involves the upper side generally pigmented and the lower side light colored, and changes in dentition and fin placement.
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Most [[species]] face either their "left" side upward (both eyes on the left side and lie on the right side) or else face their "right" side upward. Another distinguishing feature of the order is the extension of the dorsal fin onto the head. The body is highly compressed and somewhat flat on the blind side and rounded on the eyed side (Nelson 2006). Adults are almost always lacking a swim bladder (Nelson 2006).
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Halibut belong to the family of flatfish that face their "right" side upward, the righteye flounder, family Pleuronectidae. As with other righteye founders, the halibut have a lateral line that is well developed on both sides and symmetrical pelvic fins (Nelson 2006). Nelson (2006) placed the halibut, genus ''Hippoglossus'' within the subfamily Hipoglossinae, along with the genera ''Atheresthes'', ''Clidoderma'', ''Reinhardtius'', and ''Verasper''. Halibut in general are a more elongate fish than other flatfish, being only about one-third as broad (width of the body) as is long (Bigelow and Schroeder 1953). They have a relatively large, nearly symmetrical mouth, that extends to below the lower eye and small, smooth scales that are buried in the skin (IPHC 1998). The tail has been described as crescent-shaped, lunate, or concave.
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[[Image:Hippoglossus hippoglossus1.jpg|thumb|left|240px|''Hippoglossus hippoglossus'' (Altantic halibut)]]
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The '''Atlantic halibut''', ''Hippoglossus hippoglossus'', is the largest flatfish in the Atlantic and one of the largest species of teleost fish in the world. Luna and Torres (2010) report a maximum length of 4.7 meters (15 feet) and a maximum published weight of 320 kilograms (710 pounds). The Atlantic halibut's upper surface (eyed side) is a uniformly dark brown, olive or black, though younger fish are lighter and more mottled or spotted with paler marks; the underside is pale, with the larger fish having an underside often blotched or clouded with gray (called "grays" by fisherman) and sometimes patches with the same color as the upper side, while the small fish having an underside that is pure white (Bigelow and Schroeder 1953). The end of the [[caudal fin]] is concave, not rounded. It lacks dorsal spines, but has about 98-110 dorsal soft rays, and 73-85 anal soft rays (Luna and Torres 2010). The anal fin begins shortly behind the pectorals; the small ventral fins are in front of the pectorals and separated from the anal fins by considerable space (Bigelow and Schroeder 1953). The Atlantic halibut has been reported to reach a maximum lifespan of 50 years (Luna and Torres 2010; Bigelow and Schroeder 1953).
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[[image:Pacific_halibut.JPG|thumb|300px|right|The Pacific halibut is well camouflaged in its natural environment.]]
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The '''Pacific halibut''', ''Hippoglossus stenolepis'', is one of the largest teleost fish in the Pacific, with the largest sport caught halibut being 459 pounds (208 kg) near Unalaska, AK, in 1996 (Bethers 2010). Luna and Pablico (2010) report a maximum length of 2.58 meters (8.5 feet) and a maximum published weight of 363 kilograms (800 pounds). The Pacific halibut are characterized by  diamond-shaped bodies. There is a high arch in the lateral line over the pectoral fin, and it has a lunate, or crescent shaped tail. The color on the dark side varies, but tends to assume the coloration of the ocean bottom. The underside is lighter. It lacks dorsal spines, but has about 90-106 dorsal soft rays, and 69-80 anal soft rays; the pectorals are small (Luna and Pablico 2010). The dorsal fin begins above the anterior part of the pupil in the upper eye (Luna and Pablico 2010). Luna and Pablico (2010) note that the Pacific halibut has been reported to reach a maximum age of 42 years; however, other reports for the Pacific halibut has the oldest recorded specimen for a male being 55 years old and the oldest age for a female being 42 years old, based on otolith (ear bone) measurements (IPHC 1998).
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The two species were first distinguished by a Russian scientist in 1904, who differentiated the Pacific and Atlantic counterparts on the basis of such anatomical differences as the length of the pectoral fin, the shape of the body,and the shape of the scales. However, it has been debated whether or not the two actually are separate species (IPHC 1998).
  
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Although halibut size is age and sex specific , it also follows a cycle that has been related to halibut abundance. The average fish size seems to reflect density dependence in growth rate, where slower growth is associated with higher halibut (or other species) abundance, potentially due to less food available per fish.
  
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==Distribution and habitat==
  
==Overview and description==
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The Atlantic halibut is found in temperate waters of the Eastern and Western Atlantic. In the Eastern Atlantic, it is found from the Bay of Biscay to [[Iceland]], eastern [[Greenland]], Spitsbergen (island of the Svalbard archipelago in [[Norway]]), and [[Barents Sea]] (Luna and Torres 2010). In the Western Atlantic, it is found from southwestern Greenland and Labrador in Canada to the U.S. state of Virginia (Luna and Torres 2010). They are [[demersal fish]], that live on or near sand, gravel or clay bottoms at depths of between 50 and 2000 meters. They are strong simmers and able to migrate long distances.
  
Halibut are a type of "flatfish." Flatfish are an [[order (biology)|order]] (''Pleuronectiformes'') of [[ray-finned fish]] (Actinopterygii,). (Flatfish sometimes are classified as a suborder of the order [[Perciformes]].) Flatfish are a very distinctive group in that the adults are not [[Symmetry (biology)#Bilateral symmetry|bilaterally symmetrical]], the only fish with such asymmetry and the only [[vertebrate]]s that deviate so radially from the bilaterally symmetrical body plan (Grzimek et al. 2004). The young flatfish are bilaterally symmetrical and swim upright as with other fish, but early in development one of the eyes migrates to the other side of the cranium, across the top of the skull, and positions itself adjacent to the eye on the other side (Nelson 1994). The fish then swims with the two eyes on the upper side and lower side is blind. The metamorphosis also involves the upper side generally pigmented and the lower side light colored, and changes in dentition and fin placement.
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The Pacific halibut is found on the continental shelf of the North Pacific Ocean and Bering sea. In the North Pacific, they are found from Hokkaido, [[Japan]] and the Sea of Okhotsk to the southern Chukchi Sea and Point Camalu, Baja California, [[Mexico]] (Luna and Pablico 2010). The Chukchi Sea is a marginal sea of the Arctic Ocean, bounded on west by the De Long Strait, off Wrangel Island, and in the east by Point Barrow, Alaska, with the Bering Strait forming its southernmost limit. Demersal fish, the adults live on or near the bottom of the water and prefer water temperatures ranging from 3 to 8 degrees Celsius (37.4 to 46.4 degrees Fahrenheit). Strong swimmers, they are able to migrate long distances. Halibut of all ages and sizes are involved in a predominantly clockwise (Northwest to Southeast) migration from their settlement areas (Western part of the Gulf of Alaska and Bering Sea). The adult fish tend to remain on the same grounds from year to year, but make regular, seasonal migrations to the shallower feeding grounds in summer and deeper spawning grounds in winter (IPHC 1998). From November to March, mature halibut concentrate annually on spawning grounds along the edge of the continental shelf at depths from 183 to 457 meters (600 to 1,499 feet).
  
Most [[species]] face either their "left" side upward (both eyes on the left side and lie on the right side) or else face their "right" side upward. Another distinguishing feature of the order is the extension of the dorsal fin onto the head. The body is highly compressed and somewhat flat on the blind side and rounded on the eyed side (Nelson 2006). Adults are almost always lacking a swim bladder (Nelson 2006).  
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==Pacific halibut life cycle==
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In the Pacific halibut, spawning takes place during the winter months with the peak of activity occurring from December through February. Most spawning takes place off the edge of the continental shelf in deep waters of 600 to 1,500 feet (183 to 457 meters). Male halibut become sexually mature at 7 or 8 years of age while females attain sexual maturity at 8 to 12 years. Females lay half a million to four million [[egg (biology)|eggs]] annually, depending on the size of the fish (IPHC 1998).  
  
Halibut belong to the family of flatfish that face their "right" side upward, the righteye flounder, family Pleuronectidae. As with other righteye founders, the halibut have a lateral line that is well developed on both sides and symmetrical pelvic fins (Nelson 2006). Nelson (2006) placed the halibut, genus ''Hippoglossus'' within the subfamily Hipoglossinae, along with the genera ''Atheresthes'', ''Clidoderma'', ''Reinhardtius'', and ''Verasper''.
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Externally fertilized in the deep water, the eggs are free-floating and about 3 mm in diameter when released. The eggs hatch after about 15 to 20 days. The eggs develop into larva and grow, slowly drifting upward in the water. The free-floating larvae float for up to six months and can be transported several hundred miles counter-clockwise by North Pacific currents. During the free-floating stage, many changes take place in the young halibut, including the movement of the left eye to the right side of the fish. During this time the young halibut rise to the surface and are carried to shallower water by prevailing currents. At six months, the halibut has its adult form and is about 1.4 inches (3.6 cm) long. In the shallower water, young halibut then begin life as bottom dwellers. Most young halibut ultimately spend from five to seven years in rich, shallow nursery grounds like the Bering Sea (IPHC 1998).
  
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Young halibut are highly migratory and generally migrate in a clockwise direction east and south throughout the Gulf of Alaska. This clockwise migration of the young halibut counters the counter-clockwise drift of the eggs and larva. Halibut in older age classes tend to be less migratory but continue to move predominately in a clockwise direction. Mature fish are also involved in winter spawning migrations towards deeper waters migrating across several areas in some instances (IPHC 1998). Research indicated that there may be small, localized spawning populations in deep waters such as in Chatham Straight in northern Southeast Alaska. However, because of the free-floating nature of larvae and subsequent mixing of juvenile halibut from throughout the Gulf of Alaska, there is only one known genetic stock of halibut in the northern pacific.
  
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==Ecology==
  
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===Diet===
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Halibut feed on almost any animal they can fit into their mouths and being strong swimmers, they are able to capture a large variety of fishes. Animals found in their stomachs include the [[octopus]], [[crab]], [[shrimp]], [[hermit crab]], [[lamprey]], [[eel]], [[sculpin]], [[cod]], [[pollock]], [[flounder]], and other halibut. Although halibut spend most of their time near the bottom of the ocean, they may move up in the [[water column]] to feed, capturing such pelagic fish as [[salmon]], [[sand lance]], and [[herring]]. Juvenile halibut feed on small [[crustacean]]s and other bottom-dwelling organisms.
  
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===Predators===
  
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While the young halibut serves as a food source for many animals, in most [[ecosystem]]s, the adult halibut is near the top of the marine [[food chain]]. In the North Pacific, the adult Pacific halibut is preyed upon by the [[sea lion]] ''(Eumetopias jubatus)'', the [[orca]] ''(Orcinus orca)'', and the [[salmon shark]] ''(Lamna ditropis)''. Atlantic halibut are eaten by [[Pinniped|seal]]s, and are a [[staple food]] of the [[Greenland shark]].
  
Other flatfish are also called halibut. The name is derived from ''haly'' (holy) and ''butt'' (flat fish), for its popularity on Catholic holy days.<ref name=pittsburghpress>{{cite news|title=Right Eye of Halibut Moves Over to the left Side of Head|author=Uncle Ray|date=September 10, 1941|newspaper=[[The Pittsburgh Press]]|url=http://news.google.com/newspapers?id=OVIbAAAAIBAJ&sjid=c0wEAAAAIBAJ&pg=4454,336523&dq=halibut+popular+food-fish&hl=en|accessdate=2010-10-04|quote=The name "halibut" means "holy flatfish". It came from halibut being a popular food fish on holy days in England during early times.}}</ref>
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==Use as food by humans==
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[[Image:Smokedhalibut.JPG|thumb|150px|right|[[Smoking (cooking)#Types|Hot smoked]] [[Pacific halibut]]]]
  
==Physical characteristics==
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Halibut is a very popular food. The name halibut itself means "holy flafish," derived from ''haly'' (holy) and ''butt'' (flat fish), for its popularity on Catholic holy days in England (Uncle Ray 1941). Historically, halibut also have been an important food source to [[Native Americans in the United States|Native Americans]] and Canadian [[First Nations]] and continue to be a key element to many coastal subsistence economies.  
The halibut is the largest flat fish, averaging {{convert|11|-|13.5|kg|lb}}, but catch as large as {{kg to lb|333}} are reported; the largest recently recorded<ref>http://www.norwaypost.no/content/view/22349/1/</ref> was {{convert|211|kg|lb}} and {{convert|2.5|m|ft}} long.<ref>[http://www.vg.no/nyheter/innenriks/artikkel.php?artid=556516 Ulf of Sweden on Swedish National News]</ref><ref>[http://www.alaska-halibut-fishing-charters.com/halibut_biology.html Hippoglossus stenolepis - Halibut Biology from Egg to Maturity]</ref> They are gray-black on the top side with an off-white underbelly and have very small scales invisible to the naked eye embedded in their skin.<ref>http://www.adfg.state.ak.us/pubs/notebook/fish/halibut.php</ref> At birth they have an eye on each side of the head, and swim like a salmon. After six months one eye migrates to the other side, making them look more like flounder. At the same time the stationary-eyed side darkens to match the top side, while the other side remains white. This color scheme disguises halibut from above (blending with the ocean floor) and from below (blending into the light from the sky) and is known as [[countershading]].
 
  
[[Image:Alaska 2007 071.jpg|256px|thumb||right|Halibut caught off the coast of [[Raspberry Island, Alaska]]. The two fish being held up are {{convert|70|to|80|lb}} |alt=Photo of several, near human-sized white fish. Two people hold halibuts.]]
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A lean fish, with white flesh that has few bones, and a high nutritional value, the halibut is a favorite among those who eat fish. Halibut are often broiled, deep-fried or grilled while fresh. Smoking is more difficult with halibut meat than it is with salmon, due to its ultra-low fat content. Eaten fresh, the meat has a clean taste and requires little seasoning. Halibut is noted for its dense and firm texture.
  
==Diet==
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The Atlantic population is so depleted through overfishing that consumers are now cautioned to avoid Atlantic halibut. Most halibut eaten on the East coast of the United States are now from the Pacific, which has much healthier populations, and listed on the Monteray Bay Aquarium's ''Seafood Watch'' as the "best choice" as an alternative (MBA 2011).
Halibut feed on almost any animal they can fit into their mouths. Juvenile halibut feed on small crustaceans and other bottom dwelling organisms. Animals found in their stomachs include [[sand lance]], octopus, crab, salmon, [[hermit crab]]s, [[lamprey]], [[sculpin]], [[cod]], [[pollock]], [[herring]], [[flounder]] as well as other halibut. Halibut live at depths ranging from a few meters to hundreds of meters, and although they spend most of their time near the bottom,<ref name=pittsburghpress/> halibut may move up in the [[water column]] to feed. In most ecosystems the halibut is near the top of the marine [[food chain]]. In the North Pacific their common predators are the [[sea lion]] (''Eumetopias jubatus''), the [[orca]] (''Orcinus orca''), and the [[salmon shark]] (''Lamna ditropis'').
 
  
 
==Halibut fishery==
 
==Halibut fishery==
The North Pacific commercial halibut fishery dates to the late 19th century and today is one of the region's largest and most lucrative. In Canadian and U.S. waters, [[long-line fishing|longline]] predominates, using chunks of octopus ("devilfish") or other bait on circle hooks attached at regular intervals to a weighted line that can extend for several miles across the bottom. The fishing vessel retrieves the line after several hours to a day. The effects of longline gear on habitats are poorly understood but could include disturbance of sediments, [[benthic]] structures, and other structures.  
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The North Pacific commercial halibut fishery dates to the late 19th century and today is one of the region's largest and most lucrative. In Canadian and U.S. waters, [[long-line fishing|longline]] predominates, using chunks of octopus ("devilfish") or other bait on circle hooks attached at regular intervals to a weighted line that can extend for several miles across the bottom. The fishing vessel retrieves the line after several hours to a day. The effects of longline gear on habitats are poorly understood but could include disturbance of sediments, [[benthic]] structures, and other structures. The halibut are cleaned soon after being boated and are kept on ice to retain freshness.
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International management of the Pacific halibut fishery is necessary, because the species occupies waters of the United States, Canada, Russia, and possibly Japan (where the species is known to the Japanese as Ohyo), and matures slowly. Halibut do not reproduce until age eight, when about 30 inches long, so commercial capture below this length prevents breeding and is against U.S. and Canadian regulations supporting sustainability. Pacific halibut fishing is managed by the [[International Pacific Halibut Commission]] (IPHC). Fishing for the Pacific halibut is mostly concentrated in the Gulf of Alaska and the Bering Sea, off the West coast of Canada. Small halibut catches are reported in coastal Washington, Oregon, and California.
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For most of the modern era, halibut fishery operated as a derby. Regulators declared time slots when fishing was open (typically 24–48 hours at a time) and fisherman raced to catch as many pounds as they could within that interval. This approach accommodated unlimited participation in the fishery, while allowing regulators to control the quantity of fish caught annually by controlling the number and timing of openings. The approach led to unsafe fishing as openings were necessarily set before the weather was known, forcing fisherman to leave port regardless of the weather. The approach limited fresh halibut to the markets to several weeks per year, when the gluts would push down the price received by fishermen.
  
International management is necessary, because the species occupies waters of the United States, Canada, Russia, and possibly Japan (where the species is known to the Japanese as Ohyo), and matures slowly. Halibut do not reproduce until age eight, when about {{convert|30|in|cm}} long, so commercial capture below this length prevents breeding and is against U.S. and Canadian regulations supporting sustainability. Pacific halibut fishing is managed by the [[International Pacific Halibut Commission]] (IPHC).
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The Atlantic halibut was formerly a very important food fish, but due to its slow rate of population growth it is unable to recover quickly from overfishing, and the fishery has largely collapsed. Consequently, fish labelled as "halibut" is usually one of the other large flatfishes, often the Pacific halibut.  
  
For most of the modern era, halibut fishery operated as a derby. Regulators declared time slots when fishing was open (typically 24–48 hours at a time) and fisherman raced to catch as many pounds as they could within that interval. This approach accommodated unlimited participation in the fishery while allowing regulators to control the quantity of fish caught annually by controlling the number and timing of openings. The approach led to unsafe fishing as openings were necessarily set before the weather was known, forcing fisherman to leave port regardless of the weather. The approach limited fresh halibut to the markets to several weeks per year, when the gluts would push down the price received by fishermen.
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==Sport fishing==
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[[Image:Pacific Halibut Fileting.JPG|thumb|150px|Right|Sport fishing charter captain fileting an approximately 20-pound Pacific halibut caught in [[Cook Inlet]], Alaska.]]
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Sport fishing for halibut in [[Alaska]] is a very popular activity; it is a strong fighter and one of the world’s largest bony fish with an impressive yield and firm, white flesh (Schultz 2010). Over 65 percent of the effort and harvest occurs in Kachemak Bay, Southeast Alaska, the Kodiak area, and near the mouth of Deep Creek in the Lower Cook Inlet.
  
===Individual fishing quotas===
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Most anglers prefer to fish with bait, especially herring but also squid, octopus, cod pieces, or other small bottom fish, as well as herring and whole salmon heads. To get the bait down to the halibut, it is usually fished on a wire spreader or a sliding-sinker rig (Schultz 2010). Halibut are strong and fight strenuously when exposed to air. Smaller fish will usually be pulled on board with a [[Fishing gaff|gaff]] and may be clubbed or even punched in the head in order to prevent them from thrashing around on the deck. In both commercial and sport fisheries, it is not uncommon to shoot or otherwise subdue very large halibut before landing them. Alaska's sport fishery is an element of the state's tourism economy. Sportsmen’s effort and interest in catching these fish is increasing each year. In Southeast Alaska, halibut are second only to king salmon in sport angler preference (Bethers 2010).  
In 1995, U.S. regulators allocated [[individual fishing quota]]s (IFQs) to existing fishery participants based on each vessel's documented historical catch. IFQs grant holders a specific proportion of each year's [[total allowable catch]] (TAC). The fishing season is nine months. The IFQ system improved both safety and product quality by providing a stable flow of fresh halibut to the marketplace. Critics of the program suggest that, since holders can sell their quota and the fish are a public resource, the IFQ system gave a public resource to the private sector. The fisheries were managed through a treaty between The United States and Canada per recommendations of the International Pacific Halibut Commission that was formed in 1923.
 
  
There is also a significant [[sport fishing|sport fishery]] in Alaska and British Columbia where halibut are a prized game and food fish. Sport fisherman use large rods and reels with {{convert|80|-|150|lb|kg}} line, and often bait with [[herring]], large [[jigging|jigs]], or whole salmon heads. Halibut are strong and fight strenuously when exposed to air. Smaller fish will usually be pulled on board with a [[Fishing gaff|gaff]] and may be clubbed or even punched in the head in order to prevent them from thrashing around on the deck. In both commercial and sport fisheries standard procedure is to shoot or otherwise subdue very large halibut over {{convert|150|-|200|lb|kg}} before landing them. Alaska's sport fishery is an element of the state's tourism economy.
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===Conservation status===
  
==As food==
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Following [[overfishing]] the Atlantic halibut now faces a high risk of [[extinction]] in the wild, and in 1996 the [[International Union for the Conservation of Nature and Natural Resources|IUCN]] rated it as [[Endangered species|Endangered]] and placed it on its [[IUCN Red List|Red List]] (Sobel 1996).
[[File:Smokedhalibut.JPG|thumb|150px|left|[[Smoking (cooking)#Types|Hot smoked]] [[Pacific halibut]]]]
 
Halibut are often broiled, deep-fried or grilled while fresh. Smoking is more difficult with halibut meat than it is with salmon, due to its ultra-low fat content. Eaten fresh, the meat has a clean taste and requires little seasoning. Halibut is noted for its dense and firm texture.
 
  
Halibut have historically been an important food source to [[Native Americans in the United States|Native Americans]] and Canadian [[First Nations]] and continue to be a key element to many coastal subsistence economies. Accommodating the competing interests of commercial, sport, and subsistence users is a challenge.
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The Atlantic halibut is a U.S. National Marine Fisheries Service "Species of Concern." 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). The American Fisheries Society has classified the species as "Vulnerable."
  
The Atlantic population is so depleted through overfishing that it may be declared an [[endangered species]]. According to [[Seafood Watch]], consumers should avoid Atlantic halibut.<ref name="seafoodwatch">{{
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In 2010, Greenpeace International added the Atlantic halibut to its seafood red list. "The Greenpeace International seafood red list is a list of fish that are commonly sold in supermarkets around the world, and which have a very high risk of being sourced from unsustainable fisheries.
cite web
 
| url=http://www.montereybayaquarium.org/cr/SeafoodWatch/web/sfw_factsheet.aspx?gid=9
 
|title=Monterey Bay Aquarium: Seafood Watch Program-All Seafood List
 
|publisher=Monterey Bay Aquarium
 
|accessdate=2008-04-17}}</ref> Most halibut eaten on the East coast of the United States are from the Pacific.
 
  
 
==Species of the genus Hippoglossus (proper halibut)==
 
==Species of the genus Hippoglossus (proper halibut)==
[[Image:Faroe stamp 082 halibut.jpg|thumb|right|200px|Atlantic halibut (''Hippoglossus hippoglossus'') on a [[Faroe Islands|Faroese]] stamp|alt=Photo of a stamp displaying a painting of the brown side of a halibut]]
+
[[Image:Faroe stamp 082 halibut.jpg|thumb|right|200px|Atlantic halibut ''(Hippoglossus hippoglossus)'' on a Faroe Islands stamp, displaying a painting of the brown side of a halibut]]
 
* [[Atlantic halibut]], ''Hippoglossus hippoglossus''
 
* [[Atlantic halibut]], ''Hippoglossus hippoglossus''
 
* [[Pacific halibut]], ''Hippoglossus stenolepis''
 
* [[Pacific halibut]], ''Hippoglossus stenolepis''
  
==Other species sometimes called "halibut"==
+
===Other species sometimes called "halibut"===
 
* Of the same family ([[Pleuronectidae]]) as proper halibut
 
* Of the same family ([[Pleuronectidae]]) as proper halibut
 
** [[Kamchatka flounder]], ''Atheresthes evermanni'' - sometimes called "Arrowtooth halibut"
 
** [[Kamchatka flounder]], ''Atheresthes evermanni'' - sometimes called "Arrowtooth halibut"
Line 94: Line 118:
  
 
==References==
 
==References==
{{Reflist}}
 
*Clover, Charles. 2004. ''The End of the Line: How overfishing is changing the world and what we eat''. Ebury Press, London. ISBN 0-09-189780-7
 
*[[Oxford English Dictionary]], second edition, ed. John Simpson and Edmund Weiner, Clarendon Press, 1989, ISBN 0-19-861186-2.
 
"FishWatch - Pacific Halibut." NOAA :: National Marine Fisheries Service. Web. 14 Dec. 2010. <http://www.nmfs.noaa.gov/fishwatch/species/pacific_halibut.htm>.
 
  
 +
* Bigelow, H. B., and W. C. Schroeder. 1953. [http://www.gma.org/fogm/Hippoglossus_hippoglossus.htm Atlantic halibut ''Hippoglossus hippoglossus'' (Linnaeus) 1758.] ''Fishery Bulletin of the Fish and Wildlife Service'' 53(74): 249. Retrieved July 20, 2011.
  
 +
*Clover, C. 2004. ''The End of the Line: How Overfishing is Changing the World and What We Eat''. London: Ebury Press. ISBN 0091897807.
  
==Atlantic halibut==
+
* Grzimek, B., D. G. Kleiman, V. Geist, and M. C. McDade. ''Grzimek's Animal Life Encyclopedia.'' Detroit: Thomson-Gale, 2004. ISBN 0307394913.
{{Taxobox
 
| name = Atlantic halibut
 
| status = EN | status_system = IUCN2.3
 
| image = Hippoglossus hippoglossus1.jpg
 
| regnum = [[Animalia]]
 
| phylum = [[Chordata]]
 
| classis = [[Actinopterygii]]
 
| ordo = [[Pleuronectiformes]]
 
| familia = [[Pleuronectidae]]
 
| genus = ''[[Hippoglossus]]''
 
| species = '''''H. hippoglossus'''''
 
| binomial = ''Hippoglossus hippoglossus''
 
| binomial_authority = ([[Carolus Linnaeus|Linnaeus]], 1758)
 
}}
 
  
The '''Atlantic halibut''', ''Hippoglossus hippoglossus'', is a [[flatfish]] of the family [[Pleuronectidae]]. They are [[demersal fish]], that live on or near sand, gravel or clay bottoms at depths of between {{convert|50|and|2000|m|ft}}. The [[halibut]] is among the largest [[Teleostei|teleost]] (bony) fish in the world. Halibut are strong swimmers and are able to [[Fish migration|migrate]] long distances. Halibut size is not age-specific, but rather tends to follow a cycle related to halibut (and therefore food) abundance.
+
* International Pacific Halibut Commission (IPHC). 1998. [http://www.iphc.int/publications/techrep/tech0040.pdf The Pacific Halibut: Biology, fishery, and management.] ''IPCH Technical Report No. 40''. Seattle, WA: The International Pacific Halibut Commission. Retrieved July 20, 2011.
  
The native habitat of the Atlantic halibut is the temperate waters of the northern [[Atlantic Ocean|Atlantic]], from [[Labrador]] and [[Greenland]] to [[Iceland]], the [[Barents Sea]] and as far south as the [[Bay of Biscay]]. It is the largest flatfish in the Atlantic and one of the largest species of flatfish in the world, reaching lengths of up to {{convert|4.7|m|ft}} and weights of {{convert|320|kg|lb}}. Its lifespan can reach 50 years.<ref name='Fishbase'>{{cite web|url=http://www.fishbase.org/Summary/SpeciesSummary.php?id=1371 |title=Hippoglossus hippoglossus|accessdate=2009-06-22 |coauthors=Ed. Ranier Froese and Daniel Pauly |date=5 June 2009 |work=[[Fishbase]] |archiveurl= |archivedate= }}</ref><ref name='FishGulfMaine'>{{cite journal|title=Atlantic halibut|journal=FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE|year=1953|first=Henry B.|last=Bigelow|coauthors=Schroeder, William C. |volume=53|issue=74|pages=249|id= |url=http://www.gma.org/fogm/Hippoglossus_hippoglossus.htm|accessdate=2009-06-22 }}</ref>
+
* Luna, S. M., and A. G. Torres. 2010. [http://www.fishbase.org/summary/Hippoglossus-hippoglossus.html "''Hippoglossus hippoglossus (Linnaeus, 1758), Atlantic halibut."] In R. Froese and D. Pauly, ''Fishbase.org''. Retrieved July 20, 2011.
  
===Description===
+
* Monteray Bay Aquarium (MBA). 2011. Seafood Watch: Atlantic halibut. ''Seafood Watch''.
  
The Atlantic halibut is a right-eyed flounder. Its upper surface is a uniformly dark chocolate, olive or slate colour, and can be almost black (though younger fish are lighter and more mottled); the underside is pale. The end of the [[caudal fin]] is concave.<ref name='FishGulfMaine' />
+
* Nelson, J. S. 2006. ''Fishes of the World,'' 4th edition. Hoboken, NJ: John Wiley & Sons. ISBN 0471250317.
 
 
===Role in ecosystem===
 
 
 
The Atlantic halibut occupies a relatively high [[trophic level]] in the [[food chain]].
 
 
 
====Diet====
 
 
 
The diet of the Atlantic halibut consists mainly of other fish, e.g. [[cod]], [[haddock]], [[herring]], [[pogge]], [[sand eel]]s and [[capelin]], but it will also eat [[cephalopod]]s, large [[crustacean]]s and other [[benthos]] organisms.<ref name='Fishbase' /><ref name='FishGulfMaine' />
 
 
 
====Predators====
 
 
 
Atlantic halibut are eaten by [[Pinniped|seal]]s, and are a [[staple food]] of the [[Greenland shark]].<ref name='FishGulfMaine' />
 
 
 
===Commercial fishing===
 
 
 
The Atlantic halibut was formerly a very important food fish, but due to its slow rate of population growth it is unable to recover quickly from overfishing, and the fishery has largely collapsed. Consequently, fish labelled as "halibut" is usually one of the other large flatfishes, often [[Pacific halibut]], ''Hippoglossus stenolepis''.  
 
  
====Farming====
+
* Schultz, K. 2010. ''Ken Scultz’s Essentials of Fishing''. Hoboken, NJ: John Wiley and & Sons. ISBN  9780470444313.
  
Due to its popularity as a food fish, Atlantic halibut has attracted investment in [[fish farming]]. As of 2006, five countries - Canada, Norway, the UK, Iceland and Chile - were engaged in some form of Atlantic halibut [[aquaculture]] production.<ref name='FishOceansCanada'>{{cite web|url=http://www.dfo-mpo.gc.ca/aquaculture/finfish-poissons/halibut-fletan-eng.htm |title=Atlantic Halibut |accessdate=2009-06-22 |date=2006-05-31 |publisher=Fisheries and Oceans Canada }}</ref>
+
* Sobel, J. 1996. [http://www.iucnredlist.org/apps/redlist/details/10097/0 ''Hippoglossus hippoglossus'']. In ''IUCN Red List of Threatened Species'' Version 2011.1. Retrieved on July 20, 2011.
  
===Conservation status===
+
* Uncle Ray. 1941. [http://news.google.com/newspapers?id=OVIbAAAAIBAJ&sjid=c0wEAAAAIBAJ&pg=4454,336523&dq=halibut+popular+food-fish&hl=en Right eye of halibut moves over to the left side of head. ''The Pittsburgh Press'' September 10, 1941. Retrieved July 20, 2011.
  
Following [[overfishing]] the Atlantic halibut now faces a high risk of [[extinction]] in the wild, and in 1996 the [[International Union for the Conservation of Nature and Natural Resources|IUCN]] rated it as [[Endangered species|Endangered]] and placed it on its [[IUCN Red List|Red List]].<ref name='IUCN'>{{cite web|url={{IUCNlink|10097}} |title=Hippoglossus hippoglossus |accessdate=2009-06-22 |last=Sobel |first=J |year=1996 |work=[[IUCN Red List]] |publisher=[[International Union for the Conservation of Nature and Natural Resources]] }}</ref>         
 
  
The Atlantic halibut is a U.S. National Marine Fisheries Service [http://www.nmfs.noaa.gov/pr/species/concern/ Species of Concern]. Species of Concern are those species about which the U.S. government’s National Oceanic and Atmospheric Administration, [http://www.nmfs.noaa.gov 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. [http://www.nmfs.noaa.gov/pr/laws/esa/ Endangered Species Act](ESA).  The American Fisheries Society has classified the species as "Vulnerable".
+
[[Category:Life sciences]]
 
+
[[Category:Animals]]
In 2010, Greenpeace International has added the atlantic halibut to its seafood red list. "The Greenpeace International seafood red list is a list of fish that are commonly sold in supermarkets around the world, and which have a very high risk of being sourced from unsustainable fisheries."<ref>[http://www.greenpeace.org/international/seafood/red-list-of-species Greenpeace International Seafood Red list]</ref>
+
[[Category:Fishes]]
 
+
[[Category:Food]]
==Pacific halibut==
 
{{Automatic taxobox
 
| name = Pacific halibut
 
| image = Pacific_halibut.JPG
 
| image_caption = The Pacific halibut is well camouflaged in its natural environment.
 
| taxon = Hippoglossus stenolepis
 
| binomial = ''Hippoglossus stenolepis''
 
| binomial_authority = (P.J. Schmidt, 1904)
 
| range_map = pacific_halibut_range.PNG
 
| range_map_caption = Range of the Pacific halibut
 
}}
 
 
 
The Pacific halibut is found on the continental shelf of the North Pacific Ocean and Bering sea. They are [[Demersal fish|demersal]], living on or near the bottom. The [[halibut]] is among the largest [[Teleostei|teleost]] (bony) fish in the world. Halibut are strong swimmers and are able to [[Fish migration|migrate]] long distances. Halibut size is age and sex-specific, but also follows a cycle that has been related to halibut and other species abundance.
 
 
 
Pacific halibut have diamond-shaped bodies. Halibut have both eyes on their dark or upper side. The color adaption allows halibut to avoid detection from both prey and predator. Being strong swimmers, halibut are able to eat a large variety of fishes such as cod, turbot, pollock, and some invertebrates such as crab and shrimp. Most spawning takes place off the edge of the continental shelf in deep waters about {{convert|200|to|300|fathom|ft m}}. At six months of age, the young have their adult form and are about {{convert|1.4|in|cm}} long. Young halibut, up to 10 years of age, are highly migratory. Older, reproductively mature halibut move seasonally across areas and between shallower and deeper waters during and around the winter reproductive season. The oldest halibut on record (both males and females) are 55 years old<ref> http://www.iphc.int/research/biology.html </ref> based on otolith (ear bone) measurements.
 
 
 
There is a thriving commercial fishery for Pacific halibut, mainly in [[Alaska]] but also along the western coast of North America south to [[Oregon]].  Sport fishing for halibut in Alaska is a very popular activity; it is a strong fighter with an impressive yield and firm, white flesh.<ref>Schultz, Ken. Ken Scultz’s Essentials of Fishing.John Wiley and & Sons, Inc., Hoboken, New Jersey, 2010. ISBN  9780470444313, pp. 66-67</ref> Over 65 percent of the effort and harvest occurs in [[Kachemak Bay]], Southeast Alaska, the Kodiak area, and near the mouth of Deep Creek in the Lower [[Cook Inlet]]. Most halibut caught weigh {{convert|15|-|20|lb|kg}}, although individuals weighing more than {{convert|150|lb|kg}} are regularly caught. The [[International Pacific Halibut Commission]] (IPHC)<ref>[http://www.iphc.int International Pacific Halibut Commission]</ref> manages these fisheries based on large amounts of data taken annually.
 
 
 
===Distribution===
 
 
 
The Pacific halibut, ''Hippoglossus stenolepis'', is found on the [[continental shelf]] of the North Pacific Ocean and Bering Sea. Fishing for the Pacific halibut is mostly concentrated in the Gulf of Alaska and the Bering Sea, off the West coast of Canada. Small halibut catches are reported in coastal Washington, Oregon, and California. Pacific halibut is broken up to ten regularity management areas.
 
 
 
Halibut are demersal, living on or near the bottom of the water and prefer water temperatures ranging from {{convert|3|to|8|C|F|1|abbr=none}}. Pacific halibut belong to a family called Pleuronectidae. They are among the largest teleost fishes in the world. From November to March, mature halibut concentrate annually on spawning grounds along the edge of the continental shelf at depths from {{convert|183|to|457|m|ft|abbr=none}}.
 
 
 
Halibut are strong swimmers and are able to migrate long distances. Halibut of all ages and sizes are involved in a predominantly clockwise (Northwest to Southeast) migration from their settlement areas (Western part of the gulf of Alaska and Bering Sea), reproductive fish also make regular seasonal migrations from more shallow feeding grounds in summer to deeper spawning grounds in winter <ref>http://www.iphc.int/publications/annual/ar2009.pdf</ref>. Although halibut size is age and sex specific it also follows a cycle that has been related to halibut abundance. The average fish size seems to reflect density dependence in growth rate, where slower growth is associated with higher halibut (or other species) abundance, potentially due to less food available per fish.
 
 
 
===Characteristics===
 
 
 
Pacific halibut have diamond-shaped bodies. They are more elongated than most flatfishes, the width being about 1/3 of the length.  There is a high arch in the lateral line over the pectoral fin, and it has a lunate, or crescent shaped tail, which is different from other flat fishes.<ref>Schultz, Ken. Ken Scultz’s Essentials of Fishing.John Wiley and & Sons, Inc., Hoboken, New Jersey, 2010. ISBN  9780470444313, pp. 66-67</ref> Small scales are embedded in the skin. Halibut have both eyes on their dark or upper side. The color on the dark side varies, but tends to assume the coloration of the ocean bottom. The underside is lighter, appearing more like the sky from below. This color adaptation allows halibut to avoid detection by both prey and predator.
 
 
 
===Food===
 
Being strong swimmers, halibut are able to eat a large variety of fishes including cod, turbot, pollock, and some invertebrates such as octopus, crab and shrimp. Sometimes halibut leave the ocean bottom to feed on pelagic fish such as salmon, sand lance and herring.
 
 
 
===Life cycle===
 
Spawning takes place during the winter months with the peak of activity occurring from December through February. Most spawning takes place off the edge of the continental shelf in deep waters of {{convert|600|to|1500|ft|m|0}}.  Male halibut become sexually mature at 7 or 8 years of age while females attain sexual maturity at 8 to 12 years. Females lay half a million to four million eggs annually, depending on the size of the fish.<ref>[http://www.iphc.int/publications/techrep/tech0040.pdf  The Pacific Halibut: Biology, Fishery and Management] IPHC Technical Report No. 40, 1998</ref>
 
 
 
Fertilized eggs hatch after about fifteen days. Free-floating larvae float for up to six months and can be transported several hundred miles counter-clockwise by North Pacific currents. During the free-floating stage, many changes take place in the young halibut, including the movement of the left eye to the right side of the fish. During this time the young halibut rise to the surface and are carried to shallower water by prevailing currents. At six months, the halibut has its adult form and is about {{convert|1.4|in|cm}} long.<ref>[http://www.iphc.int/publications/techrep/tech0040.pdf  The Pacific Halibut: Biology, Fishery and Management] IPHC Technical Report No. 40, 1998</ref> In the shallower water, young halibut then begin life as bottom dwellers. Most young halibut ultimately spend from five to seven years in rich, shallow nursery grounds like the Bering Sea.
 
 
 
Young halibut are highly migratory and generally migrate in a clockwise direction east and south throughout the Gulf of Alaska. Halibut in older age classes tend to be less migratory but continue to move predominately on a clockwise direction. Mature fish are also involved in winter spawning migrations towards deeper waters migrating across several areas in some instances <ref>http://www.iphc.int/publications/annual/ar2009.pdf</ref>. Research indicated that there may be small, localized spawning populations in deep waters such as in Chatham Straight in northern Southeast Alaska. However, because of the free-floating nature of larvae and subsequent mixing of juvenile halibut from throughout the Gulf of Alaska, there is only one known genetic stock of halibut in the northern pacific.
 
 
 
Halibut growth rates vary depending on locations and habitat conditions, but females grow faster than males. The oldest recorded female and male were 55 years old. The largest recorded sport caught halibut was {{convert|459|lb|kg}} near Unalaska, AK, in 1996.<ref>Bethers, Mike. Pacific Halibut. Alaska Department of Fish & Game. [http://www.adfg.state.ak.us/pubs/notebook/fish.halibut.php Read Online] Accessed 5/23/2010</ref>
 
 
 
===Length and weight===
 
[[Image:Pacific Halibut WL.jpg|300px | right | thumb |]]
 
As Pacific halibut grow longer, they increase in weight.  The relationship between length and weight is not linear.  The relationship between total length (L, in inches) and total weight (W, in pounds) for nearly all species of fish can be expressed by an equation of the form:
 
<math>W = cL^b\!\,</math>
 
 
 
Invariably, b is close to 3.0 for all species, and c is a constant that varies among species.<ref>R. O. Anderson and R. M. Neumann, Length, Weight, and Associated Structural Indices, in Fisheries Techniques, second edition, B.E. Murphy and D.W. Willis, eds., American Fisheries Society, 1996.</ref> A weight-length relationship based on a least-squares fit to data published in 2003 by the International Pacific Halibut Commission (IHPC)<ref>[http://www.iphc.washington.edu/HALCOM/pubs/bulletin/lenwtimp.pdf Halibut weight/length chart (Imperial) published by the IHPC 2003]</ref> suggests that, for pacific halibut, ''c'' = 0.00018872 and ''b'' =  3.24.
 
 
 
This relationship predicts that a 20&nbsp;inch Pacific halibut will weigh about three pounds, a 36&nbsp;inch halibut will weigh about 20 pounds, and that a 58&nbsp;inch halibut will weigh about 100 pounds.
 
 
 
===Commercial fishing===
 
[[File:Smokedhalibut.JPG|thumb|right|Smoked Pacific halibut on smoker racks]]
 
Commercial halibut fishing probably began in 1888 when three sailing ships from New England fished off the coast of Washington State.<ref>Bethers, Mike. Pacific Halibut. Alaska Department of Fish & Game. [http://www.adfg.state.ak.us/pubs/notebook/fish.halibut.php Read Online] Accessed 5/23/2010</ref>
 
As the industry grew, company-owned steamers carrying several smaller dories, from which the fishing was actually conducted, dominated the halibut industry. Subsequently, smaller boats of schooner design from {{convert|60|to|100|ft|m|1}} were used by fishermen. These boats carried crews of five to eight and were specifically designed for halibut fishing. Today, many types of boats are used in the halibut industry. Most of the old-style halibut schooners have been replaced by more versatile craft that may also be used in commercial salmon serine, troll, gillnet, and crab fisheries.
 
 
 
Halibut gear consists of units of leaded ground line in lengths of {{convert|100|fathom|ft m|0}} referred to as “skates.” Each skate has approximately 100 hooks attached to it. “Gangens,” or the lines to which the hooks are attached are either tied to or snapped onto the ground line. A “set” consists of one or more baited skates tied together and laid on the ocean bottom with anchors at each end. Each end has a float line with a buoy attached. Hooks are typically baited with frozen herring, octopus, or other fresh fish. Depending on the fishing ground, depth, time of year, and bait used, a set is pulled 2 to 20 hours after being fished. Longlines are normally pulled off the ocean floor by a hydraulic puller of some type. The halibut are cleaned soon after being boated and are kept on ice to retain freshness.
 
[[Homer, Alaska]] claims the title of "Halibut Capital of the world" because of the large  volume of both sport and commercial halibut fishing in the area.
 
 
 
===Sport fishing===
 
[[Image:Pacific Halibut Fileting.JPG|thumb|left| 150px| Sport fishing charter captain fileting an approximately 20-pound Pacific halibut caught in [[Cook Inlet]], Alaska.]]
 
Sport fishing for halibut in Alaska is a very popular activity; it is a strong fighter and one of the world’s largest bony fish with an impressive yield and firm, white flesh.<ref>Schultz, Ken. Ken Scultz’s Essentials of Fishing.John Wiley and & Sons, Inc., Hoboken, New Jersey, 2010. ISBN  9780470444313, pp. 66-67</ref> Over 65 percent of the effort and harvest occurs in Kachemak Bay, Southeast Alaska, the Kodiak area, and near the mouth of Deep Creek in the Lower Cook Inlet.
 
 
 
Halibut taken by anglers are generally {{convert|15|to|20|lb|kg}} in weight; however, fish over {{convert|150|lb|kg}} are regularly caught. The current Alaska state record for a sport-caught halibut is {{convert|459|lb|kg|abbr=on}},<ref>Bethers, Mike. Pacific Halibut. Alaska Department of Fish & Game. [http://www.adfg.state.ak.us/pubs/notebook/fish.halibut.php Read Online] Accessed 5/23/2010</ref> and a fish must weigh at least {{convert|250|lb|kg|0|abbr=on}} to qualify for the state’s trophy fish program. Anglers use stout saltwater gear to harvest halibut. Most anglers prefer to fish with bait, especially herring but also squid, octopus, cod pieces, or other small bottom fish. To get the bait down to the halibut, it is usually fished on a wire spreader or a sliding-sinker rig with sinker size {{convert|4|oz|g|0}} to {{convert|4|lb|kg|2}}, depending on such factors as depth and current.  <ref>Schultz, Ken. Ken Scultz’s Essentials of Fishing.John Wiley and & Sons, Inc., Hoboken, New Jersey, 2010. ISBN  9780470444313, pp. 66-67</ref>
 
 
 
Halibut, along with salmon, provide substinence for several Pacific Coast native groups. Many of these groups smoke and dry the halibut for winter use.  Sportsmen’s effort and interest in catching these delicious fish is increasing each year. In Southeast Alaska, halibut are second only to king salmon in sport angler preference.<ref>Bethers, Mike. Pacific Halibut. Alaska Department of Fish & Game. [http://www.adfg.state.ak.us/pubs/notebook/fish.halibut.php Read Online] Accessed 5/23/2010</ref> Fishing for Pacific halibut is regulated by the International Pacific Halibut Commission. Members from the United States and Canada meet yearly to review research, check the progress of the commercial fishery, and make regulations for the next fishing season. The management of halibut fishing by this commission is intended to allow a sustainable yield of halibut.
 
 
 
==References==
 
 
 
* Grzimek, B., D. G. Kleiman, V. Geist, and M. C. McDade. ''Grzimek's Animal Life Encyclopedia.'' Detroit: Thomson-Gale, 2004. ISBN 0307394913.
 
 
 
* Nelson, J. S. 2006. ''Fishes of the World,'' 4th edition. Hoboken, NJ: John Wiley & Sons. ISBN 0471250317.
 
  
[[Category:Pleuronectidae]]
 
[[Category:Seafood]]
 
[[Category:Fauna of Greenland]]
 
[[Category:Edible fish]]
 
[[Category:Commercial fish]]
 
[[Category:Alaskan cuisine]]
 
  
 
{{credit|Halibut|438050332|Pacific_halibut|434195875|Atlantic_halibut|423888533}}
 
{{credit|Halibut|438050332|Pacific_halibut|434195875|Atlantic_halibut|423888533}}

Latest revision as of 13:25, 24 January 2023

Halibut
Pacific halibut (H. stenolepis). Halibut tend to be a mottled brown on their upward-facing side and white on their downside
Pacific halibut (H. stenolepis).
Halibut tend to be a mottled brown on their upward-facing side and white on their downside
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Pleuronectiformes
Family: Pleuronectidae
Genus: Hippoglossus
Species

H. hippoglossus (Atlantic halibut)
H. stenolepis (Pacific halibut)

Halibut is the common name for any flatfish (order Pleuronectiformes) belonging to the genus Hippoglossus from the family of right-eye flounders (Pleuronectidae), of which there are two extant species, the Atlantic halibut (H. hippoglossus) and the Pacific halibut (H. stenolepis). Demersal fish, that live near the bottom of the ocean as adults, halibut are characterized by having both eyes on their dark or upper side and somewhat more elongated bodies than other flatfish, with a somewhat lunate caudal fin. They also exhibit large size, being among the largest teleost (bony) fish in the world. They also are strong swimmers and can migrate long distances. The common name halibut also is used for some other species of flatfish.

The Atlantic halibut is native to the temperate waters of the northern Atlantic, from Labrador and Greenland to Iceland, the Barents Sea and as far south as the Bay of Biscay. The Pacific halibut is found on the continental shelf of the North Pacific Ocean and Bering sea.

Halibut is a very popular food, with lean, white, sweet-flavored flesh with few bones and high nutritional value. As a result, a lucrative halibut fishery has developed, and it is also popular in sport fishing. Halibut also is important ecologically as an integral part of marine food chains. An adult female can produce millions of eggs, with the eggs and larva providing food for numerous marine animals. And while the adult halibut is so large that it is near the top of the food chain, it too may be preyed upon by sea lions, orcas, sharks, and seals. On the other hand, the strong-swimming halibut is able to capture and feed upon a wide variety of fish, crustaceans, and mollusks.

Despite these ecological, commercial, recreational, and nutritional values, overfishing of the Atlantic halibut has resulted in being rated as an endangered species, with a high risk of extinction in the wild. A contributing factor is that the halibut does not reach sexual maturity until roughly eight years of age. The Pacific halibut, however, continues to have healthy populations, and remains a lucrative commercial fishery.

Overview and description

Halibut caught off the coast of Raspberry Island, Alaska. The two fish being held up are 70 to 80 pounds.

Halibut are a type of "flatfish." Flatfish are an order (Pleuronectiformes) of ray-finned fish (Actinopterygii,). (Flatfish sometimes are classified as a suborder of the order Perciformes.) Flatfish are a very distinctive group in that the adults are not bilaterally symmetrical, the only fish with such asymmetry and the only vertebrates that deviate so radially from the bilaterally symmetrical body plan (Grzimek et al. 2004). The young flatfish are bilaterally symmetrical and swim upright as with other fish, but early in development one of the eyes migrates to the other side of the cranium, across the top of the skull, and positions itself adjacent to the eye on the other side (Nelson 1994). The fish then swims with the two eyes on the upper side and lower side is blind. The metamorphosis also involves the upper side generally pigmented and the lower side light colored, and changes in dentition and fin placement.

Most species face either their "left" side upward (both eyes on the left side and lie on the right side) or else face their "right" side upward. Another distinguishing feature of the order is the extension of the dorsal fin onto the head. The body is highly compressed and somewhat flat on the blind side and rounded on the eyed side (Nelson 2006). Adults are almost always lacking a swim bladder (Nelson 2006).

Halibut belong to the family of flatfish that face their "right" side upward, the righteye flounder, family Pleuronectidae. As with other righteye founders, the halibut have a lateral line that is well developed on both sides and symmetrical pelvic fins (Nelson 2006). Nelson (2006) placed the halibut, genus Hippoglossus within the subfamily Hipoglossinae, along with the genera Atheresthes, Clidoderma, Reinhardtius, and Verasper. Halibut in general are a more elongate fish than other flatfish, being only about one-third as broad (width of the body) as is long (Bigelow and Schroeder 1953). They have a relatively large, nearly symmetrical mouth, that extends to below the lower eye and small, smooth scales that are buried in the skin (IPHC 1998). The tail has been described as crescent-shaped, lunate, or concave.

Hippoglossus hippoglossus (Altantic halibut)

The Atlantic halibut, Hippoglossus hippoglossus, is the largest flatfish in the Atlantic and one of the largest species of teleost fish in the world. Luna and Torres (2010) report a maximum length of 4.7 meters (15 feet) and a maximum published weight of 320 kilograms (710 pounds). The Atlantic halibut's upper surface (eyed side) is a uniformly dark brown, olive or black, though younger fish are lighter and more mottled or spotted with paler marks; the underside is pale, with the larger fish having an underside often blotched or clouded with gray (called "grays" by fisherman) and sometimes patches with the same color as the upper side, while the small fish having an underside that is pure white (Bigelow and Schroeder 1953). The end of the caudal fin is concave, not rounded. It lacks dorsal spines, but has about 98-110 dorsal soft rays, and 73-85 anal soft rays (Luna and Torres 2010). The anal fin begins shortly behind the pectorals; the small ventral fins are in front of the pectorals and separated from the anal fins by considerable space (Bigelow and Schroeder 1953). The Atlantic halibut has been reported to reach a maximum lifespan of 50 years (Luna and Torres 2010; Bigelow and Schroeder 1953).

The Pacific halibut is well camouflaged in its natural environment.

The Pacific halibut, Hippoglossus stenolepis, is one of the largest teleost fish in the Pacific, with the largest sport caught halibut being 459 pounds (208 kg) near Unalaska, AK, in 1996 (Bethers 2010). Luna and Pablico (2010) report a maximum length of 2.58 meters (8.5 feet) and a maximum published weight of 363 kilograms (800 pounds). The Pacific halibut are characterized by diamond-shaped bodies. There is a high arch in the lateral line over the pectoral fin, and it has a lunate, or crescent shaped tail. The color on the dark side varies, but tends to assume the coloration of the ocean bottom. The underside is lighter. It lacks dorsal spines, but has about 90-106 dorsal soft rays, and 69-80 anal soft rays; the pectorals are small (Luna and Pablico 2010). The dorsal fin begins above the anterior part of the pupil in the upper eye (Luna and Pablico 2010). Luna and Pablico (2010) note that the Pacific halibut has been reported to reach a maximum age of 42 years; however, other reports for the Pacific halibut has the oldest recorded specimen for a male being 55 years old and the oldest age for a female being 42 years old, based on otolith (ear bone) measurements (IPHC 1998).

The two species were first distinguished by a Russian scientist in 1904, who differentiated the Pacific and Atlantic counterparts on the basis of such anatomical differences as the length of the pectoral fin, the shape of the body,and the shape of the scales. However, it has been debated whether or not the two actually are separate species (IPHC 1998).

Although halibut size is age and sex specific , it also follows a cycle that has been related to halibut abundance. The average fish size seems to reflect density dependence in growth rate, where slower growth is associated with higher halibut (or other species) abundance, potentially due to less food available per fish.

Distribution and habitat

The Atlantic halibut is found in temperate waters of the Eastern and Western Atlantic. In the Eastern Atlantic, it is found from the Bay of Biscay to Iceland, eastern Greenland, Spitsbergen (island of the Svalbard archipelago in Norway), and Barents Sea (Luna and Torres 2010). In the Western Atlantic, it is found from southwestern Greenland and Labrador in Canada to the U.S. state of Virginia (Luna and Torres 2010). They are demersal fish, that live on or near sand, gravel or clay bottoms at depths of between 50 and 2000 meters. They are strong simmers and able to migrate long distances.

The Pacific halibut is found on the continental shelf of the North Pacific Ocean and Bering sea. In the North Pacific, they are found from Hokkaido, Japan and the Sea of Okhotsk to the southern Chukchi Sea and Point Camalu, Baja California, Mexico (Luna and Pablico 2010). The Chukchi Sea is a marginal sea of the Arctic Ocean, bounded on west by the De Long Strait, off Wrangel Island, and in the east by Point Barrow, Alaska, with the Bering Strait forming its southernmost limit. Demersal fish, the adults live on or near the bottom of the water and prefer water temperatures ranging from 3 to 8 degrees Celsius (37.4 to 46.4 degrees Fahrenheit). Strong swimmers, they are able to migrate long distances. Halibut of all ages and sizes are involved in a predominantly clockwise (Northwest to Southeast) migration from their settlement areas (Western part of the Gulf of Alaska and Bering Sea). The adult fish tend to remain on the same grounds from year to year, but make regular, seasonal migrations to the shallower feeding grounds in summer and deeper spawning grounds in winter (IPHC 1998). From November to March, mature halibut concentrate annually on spawning grounds along the edge of the continental shelf at depths from 183 to 457 meters (600 to 1,499 feet).

Pacific halibut life cycle

In the Pacific halibut, spawning takes place during the winter months with the peak of activity occurring from December through February. Most spawning takes place off the edge of the continental shelf in deep waters of 600 to 1,500 feet (183 to 457 meters). Male halibut become sexually mature at 7 or 8 years of age while females attain sexual maturity at 8 to 12 years. Females lay half a million to four million eggs annually, depending on the size of the fish (IPHC 1998).

Externally fertilized in the deep water, the eggs are free-floating and about 3 mm in diameter when released. The eggs hatch after about 15 to 20 days. The eggs develop into larva and grow, slowly drifting upward in the water. The free-floating larvae float for up to six months and can be transported several hundred miles counter-clockwise by North Pacific currents. During the free-floating stage, many changes take place in the young halibut, including the movement of the left eye to the right side of the fish. During this time the young halibut rise to the surface and are carried to shallower water by prevailing currents. At six months, the halibut has its adult form and is about 1.4 inches (3.6 cm) long. In the shallower water, young halibut then begin life as bottom dwellers. Most young halibut ultimately spend from five to seven years in rich, shallow nursery grounds like the Bering Sea (IPHC 1998).

Young halibut are highly migratory and generally migrate in a clockwise direction east and south throughout the Gulf of Alaska. This clockwise migration of the young halibut counters the counter-clockwise drift of the eggs and larva. Halibut in older age classes tend to be less migratory but continue to move predominately in a clockwise direction. Mature fish are also involved in winter spawning migrations towards deeper waters migrating across several areas in some instances (IPHC 1998). Research indicated that there may be small, localized spawning populations in deep waters such as in Chatham Straight in northern Southeast Alaska. However, because of the free-floating nature of larvae and subsequent mixing of juvenile halibut from throughout the Gulf of Alaska, there is only one known genetic stock of halibut in the northern pacific.

Ecology

Diet

Halibut feed on almost any animal they can fit into their mouths and being strong swimmers, they are able to capture a large variety of fishes. Animals found in their stomachs include the octopus, crab, shrimp, hermit crab, lamprey, eel, sculpin, cod, pollock, flounder, and other halibut. Although halibut spend most of their time near the bottom of the ocean, they may move up in the water column to feed, capturing such pelagic fish as salmon, sand lance, and herring. Juvenile halibut feed on small crustaceans and other bottom-dwelling organisms.

Predators

While the young halibut serves as a food source for many animals, in most ecosystems, the adult halibut is near the top of the marine food chain. In the North Pacific, the adult Pacific halibut is preyed upon by the sea lion (Eumetopias jubatus), the orca (Orcinus orca), and the salmon shark (Lamna ditropis). Atlantic halibut are eaten by seals, and are a staple food of the Greenland shark.

Use as food by humans

Hot smoked Pacific halibut

Halibut is a very popular food. The name halibut itself means "holy flafish," derived from haly (holy) and butt (flat fish), for its popularity on Catholic holy days in England (Uncle Ray 1941). Historically, halibut also have been an important food source to Native Americans and Canadian First Nations and continue to be a key element to many coastal subsistence economies.

A lean fish, with white flesh that has few bones, and a high nutritional value, the halibut is a favorite among those who eat fish. Halibut are often broiled, deep-fried or grilled while fresh. Smoking is more difficult with halibut meat than it is with salmon, due to its ultra-low fat content. Eaten fresh, the meat has a clean taste and requires little seasoning. Halibut is noted for its dense and firm texture.

The Atlantic population is so depleted through overfishing that consumers are now cautioned to avoid Atlantic halibut. Most halibut eaten on the East coast of the United States are now from the Pacific, which has much healthier populations, and listed on the Monteray Bay Aquarium's Seafood Watch as the "best choice" as an alternative (MBA 2011).

Halibut fishery

The North Pacific commercial halibut fishery dates to the late 19th century and today is one of the region's largest and most lucrative. In Canadian and U.S. waters, longline predominates, using chunks of octopus ("devilfish") or other bait on circle hooks attached at regular intervals to a weighted line that can extend for several miles across the bottom. The fishing vessel retrieves the line after several hours to a day. The effects of longline gear on habitats are poorly understood but could include disturbance of sediments, benthic structures, and other structures. The halibut are cleaned soon after being boated and are kept on ice to retain freshness.

International management of the Pacific halibut fishery is necessary, because the species occupies waters of the United States, Canada, Russia, and possibly Japan (where the species is known to the Japanese as Ohyo), and matures slowly. Halibut do not reproduce until age eight, when about 30 inches long, so commercial capture below this length prevents breeding and is against U.S. and Canadian regulations supporting sustainability. Pacific halibut fishing is managed by the International Pacific Halibut Commission (IPHC). Fishing for the Pacific halibut is mostly concentrated in the Gulf of Alaska and the Bering Sea, off the West coast of Canada. Small halibut catches are reported in coastal Washington, Oregon, and California.

For most of the modern era, halibut fishery operated as a derby. Regulators declared time slots when fishing was open (typically 24–48 hours at a time) and fisherman raced to catch as many pounds as they could within that interval. This approach accommodated unlimited participation in the fishery, while allowing regulators to control the quantity of fish caught annually by controlling the number and timing of openings. The approach led to unsafe fishing as openings were necessarily set before the weather was known, forcing fisherman to leave port regardless of the weather. The approach limited fresh halibut to the markets to several weeks per year, when the gluts would push down the price received by fishermen.

The Atlantic halibut was formerly a very important food fish, but due to its slow rate of population growth it is unable to recover quickly from overfishing, and the fishery has largely collapsed. Consequently, fish labelled as "halibut" is usually one of the other large flatfishes, often the Pacific halibut.

Sport fishing

Sport fishing charter captain fileting an approximately 20-pound Pacific halibut caught in Cook Inlet, Alaska.

Sport fishing for halibut in Alaska is a very popular activity; it is a strong fighter and one of the world’s largest bony fish with an impressive yield and firm, white flesh (Schultz 2010). Over 65 percent of the effort and harvest occurs in Kachemak Bay, Southeast Alaska, the Kodiak area, and near the mouth of Deep Creek in the Lower Cook Inlet.

Most anglers prefer to fish with bait, especially herring but also squid, octopus, cod pieces, or other small bottom fish, as well as herring and whole salmon heads. To get the bait down to the halibut, it is usually fished on a wire spreader or a sliding-sinker rig (Schultz 2010). Halibut are strong and fight strenuously when exposed to air. Smaller fish will usually be pulled on board with a gaff and may be clubbed or even punched in the head in order to prevent them from thrashing around on the deck. In both commercial and sport fisheries, it is not uncommon to shoot or otherwise subdue very large halibut before landing them. Alaska's sport fishery is an element of the state's tourism economy. Sportsmen’s effort and interest in catching these fish is increasing each year. In Southeast Alaska, halibut are second only to king salmon in sport angler preference (Bethers 2010).

Conservation status

Following overfishing the Atlantic halibut now faces a high risk of extinction in the wild, and in 1996 the IUCN rated it as Endangered and placed it on its Red List (Sobel 1996).

The Atlantic halibut is a U.S. National Marine Fisheries Service "Species of Concern." 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). The American Fisheries Society has classified the species as "Vulnerable."

In 2010, Greenpeace International added the Atlantic halibut to its seafood red list. "The Greenpeace International seafood red list is a list of fish that are commonly sold in supermarkets around the world, and which have a very high risk of being sourced from unsustainable fisheries.

Species of the genus Hippoglossus (proper halibut)

Atlantic halibut (Hippoglossus hippoglossus) on a Faroe Islands stamp, displaying a painting of the brown side of a halibut
  • Atlantic halibut, Hippoglossus hippoglossus
  • Pacific halibut, Hippoglossus stenolepis

Other species sometimes called "halibut"

  • Of the same family (Pleuronectidae) as proper halibut
    • Kamchatka flounder, Atheresthes evermanni - sometimes called "Arrowtooth halibut"
    • Roundnose flounder, Eopsetta grigorjewi - often called "Shotted halibut"
    • Greenland turbot, Reinhardtius hippoglossoides - often called "Greenland halibut"
    • Spotted halibut, Verasper variegatus
  • Family Paralichthyidae
    • California flounder, Paralichthys californicus - sometimes called "California halibut"
    • Olive flounder, Paralichthys olivaceus - sometimes called "Bastard halibut"
  • Family Psettodidae
    • Indian spiny turbot - sometimes called "Indian halibut"
  • Family Carangidae (jack family, not a flatfish)
    • Black pomfret, Parastromateus niger - sometimes called "Australian halibut"

References
ISBN links support NWE through referral fees

  • Clover, C. 2004. The End of the Line: How Overfishing is Changing the World and What We Eat. London: Ebury Press. ISBN 0091897807.
  • Grzimek, B., D. G. Kleiman, V. Geist, and M. C. McDade. Grzimek's Animal Life Encyclopedia. Detroit: Thomson-Gale, 2004. ISBN 0307394913.
  • Monteray Bay Aquarium (MBA). 2011. Seafood Watch: Atlantic halibut. Seafood Watch.
  • Nelson, J. S. 2006. Fishes of the World, 4th edition. Hoboken, NJ: John Wiley & Sons. ISBN 0471250317.
  • Schultz, K. 2010. Ken Scultz’s Essentials of Fishing. Hoboken, NJ: John Wiley and & Sons. ISBN 9780470444313.
  • Sobel, J. 1996. Hippoglossus hippoglossus. In IUCN Red List of Threatened Species Version 2011.1. Retrieved on July 20, 2011.


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