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  • Mackerel 

    Mackerel is a common name applied to a number of different species of pelagic fish, mostly from the family Scombridae. They are found in both temperate and tropical seas, mostly living along the coast or offshore in the oceanic environment.

    Mackerel species typically have deeply forked tails and vertical “tiger-like” stripes on their backs with an iridescent green-blue quality.[2][3] Many are restricted in their distribution ranges and live in separate populations or fish stocks based on geography. Some stocks migrate in large schools along the coast to suitable spawning grounds, where they spawn in fairly shallow waters. After spawning they return the way they came in smaller schools to suitable feeding grounds, often near an area of upwelling. From there they may move offshore into deeper waters and spend the winter in relative inactivity. Other stocks migrate across oceans.

    Some species of mackerel migrate in schools for long distances along the coast and other species cross oceans

    Smaller mackerel are forage fish for larger predators, including larger mackerel and Atlantic cod.[4] Flocks of seabirds, whales, dolphins, sharks, and schools of larger fish such as tuna and marlin follow mackerel schools and attack them in sophisticated and cooperative ways. Mackerel flesh is high in omega-3 oils and is intensively harvested by humans. In 2009, over 5 million tons were landed by commercial fishermen.[1] Sport fishermen value the fighting abilities of the king mackerel.[5]

    Species

    [edit]

    Over 30 different species, principally belonging to the family Scombridae, are commonly referred to as mackerel. The term “mackerel” is derived from Old French and may have originally meant either “marked, spotted” or “pimp, procurer”. The latter connection is not altogether clear, but mackerel spawn enthusiastically in shoals near the coast, and medieval ideas on animal procreation were creative.[6]

    Scombroid mackerels

    [edit]

    About 21 species in the family Scombridae are commonly called mackerel. The type species for the scombroid mackerel is the Atlantic mackerelScomber scombrus. Until recently, Atlantic chub mackerel and Indo-Pacific chub mackerel were thought to be subspecies of the same species. In 1999, Collette established, on molecular and morphological considerations, that these are separate species.[7] Mackerel are smaller with shorter lifecycles than their close relatives, the tuna, which are also members of the same family.[8][9]

    Scombrini, the true mackerels

    [edit]

    The true mackerels belong to the tribe Scombrini.[10] The tribe consists of seven species, each belonging to one of two generaScomber or Rastrelliger.[11][12]

    hideTrue Mackerels (tribe Scombrini)
    Common nameScientific nameMaximum
    length
    Common
    length
    Maximum
    weight
    Maximum
    age
    Trophic
    level
    FishBaseFAOIUCN status
    Short mackerelRastrelliger brachysoma
    (Bleeker, 1851)
    34.5 cm (13.6 in)20 cm (7.9 in)2.72[13][14] Data deficient[15]
    Island mackerelR. faughni
    (Matsui, 1967)
    20 cm (7.9 in)0.75 kg (1.7 lb)3.4[16] Data deficient[17]
    Indian mackerelR. kanagurta
    (Cuvier, 1816)
    35 cm (14 in)25 cm (9.8 in)4 years3.19[18][19] Data deficient[20]
    Blue mackerelScomber australasicus
    (Cuvier, 1832)
    44 cm (17 in)30 cm (12 in)1.36 kg (3.0 lb)4.2[21] Least concern[22]
    Atlantic chub mackerelS. colias
    (Gmelin, 1789)
    3.91[23] Least concern[24]
    Chub mackerelS. japonicus
    (Houttuyn, 1782)
    64 cm (25 in)30 cm (12 in)2.9 kg (6.4 lb)18 years3.09[25][26] Least concern[27]
    Atlantic mackerelS. scombrus
    (Linnaeus, 1758)
    66 cm (26 in)30 cm (12 in)3.4 kg (7.5 lb)12 years west
    18 years east
    3.65[28][29] Least concern[7]

    Scomberomorini, the Spanish mackerels

    [edit]

    The Spanish mackerels belong to the tribe Scomberomorini, which is the “cousin tribe” of the true mackerels.[30] This tribe consists of 21 species in all—18 of those are classified into the genus Scomberomorus,[31] two into Grammatorcynus,[32] and a single species into the monotypic genus Acanthocybium.[33]

    hideSpanish Mackerels (tribe Scomberomorini)
    Common nameScientific nameMaximum
    length
    Common
    length
    Maximum
    weight
    Maximum
    age
    Trophic
    level
    FishBaseFAOIUCN status
    WahooAcanthocybium solandri
    (Cuvier in Cuvier and Valenciennes, 1832)
    250 cm (98 in)170 cm (67 in)83 kg (183 lb)years4.4[34] Least concern[35]
    Shark mackerelGrammatorcynus bicarinatus
    (Quoy & Gaimard, 1825)
    112 cm (44 in)13.5 kg (30 lb)4.5[36] Least concern[37]
    Double-lined mackerelG. bilineatus
    (Rüppell, 1836)
    100 cm (39 in)50 cm (20 in)3.5 kg (7.7 lb)4.18[38] Least concern[39]
    Serra Spanish mackerelScomberomorus brasiliensis
    (Collette, Russo & Zavala-Camin, 1978)
    125 cm (49 in)65 cm (26 in)6.7 kg (15 lb)3.31[40] Least concern[41]
    King mackerelS. cavalla
    (Cuvier, 1829)
    184 cm (72 in)70 cm (28 in)45 kg (99 lb)14 years4.5[42][43] Least concern[44]
    Narrow-barred Spanish mackerelS. commerson
    (Lacepède, 1800)
    240 cm (94 in)120 cm (47 in)70 kg (150 lb)4.5[45][46] Near threatened[47]
    Monterey Spanish mackerelS. concolor
    (Lockington, 1879)
    87 cm (34 in)3.6 kg (7.9 lb)4.24[48][49] Vulnerable[50]
    Indo-Pacific king mackerelS. guttatus
    (Bloch & Schneider, 1801)
    81.5 cm (32.1 in)55 cm (22 in)4.5 kg (9.9 lb)16 years4.28[51][52] Data deficient[53]
    Korean mackerelS. koreanus
    (Kishinouye, 1915)
    150 cm (59 in)60 cm (24 in)15 kg (33 lb)4.2[54][55] Least concern[56]
    Streaked Spanish mackerelS. lineolatus
    (Cuvier, 1829)
    80 cm (31 in)70 cm (28 in)4.1 kg (9.0 lb)4.5[57] Least concern[58]
    Atlantic Spanish mackerelS. maculatus
    (Mitchill, 1815)
    91 cm (36 in)5.89 kg (13.0 lb)5 years4.5[59][60] Least concern[61]
    Papuan Spanish mackerelS. multiradiatus
    Munro, 1964
    35 cm (14 in)0.5 kg (1.1 lb)4.0[62] Least concern[63]
    Australian spotted mackerelS. munroi
    (Collette & Russo, 1980)
    104 cm (41 in)10.2 kg (22 lb)4.3[64] Near threatened[65]
    Japanese Spanish mackerelS. niphonius
    (Cuvier, 1832)
    100 cm (39 in)10.5 kg (23 lb)4.5[66][55][67] Data deficient[68]
    Queen mackerelS. plurilineatus
    Fourmanoir, 1966
    120 cm (47 in)12.5 kg (28 lb)4.2[69] Data deficient[70]
    Queensland school mackerelS. queenslandicus
    (Munro, 1943)
    100 cm (39 in)80 cm (31 in)12.2 kg (27 lb)4.5[71] Least concern[72]
    Cero mackerelS. regalis
    (Bloch, 1793)
    183 cm (72 in)8.2 kg (18 lb)4.5[73] Least concern[74]
    Broadbarred king mackerelS. semifasciatus
    (Macleay, 1883)
    120 cm (47 in)10 kg (22 lb)10 years4.5[75] Least concern[76]
    Pacific sierraS. sierra
    (Cuvier, 1832)
    99 cm (39 in)60 cm (24 in)8.2 kg (18 lb)4.5[77][55] Least concern[78]
    Chinese mackerelS. sinensis
    (Cuvier, 1832)
    247 cm (97 in)100 cm (39 in)131 kg (289 lb)4.5[79][55] Data deficient[78]
    West African Spanish mackerelS. tritor
    (Cuvier, 1832)
    100 cm (39 in)75 cm (30 in)6 kg (13 lb)4.26[80] Least concern[78]

    Other mackerel

    [edit]

    In addition, a number of species with mackerel-like characteristics in the families CarangidaeHexagrammidae and Gempylidae are commonly referred to as mackerel. Some confusion had occurred between the Pacific jack mackerel (Trachurus symmetricus) and the heavily harvested Chilean jack mackerel (T. murphyi). These have been thought at times to be the same species, but are now recognized as separate species.[81]

    hideOther mackerel species
    FamilyCommon nameScientific nameMaximum
    length
    Common
    length
    Maximum
    weight
    Maximum
    age
    Trophic
    level
    FishBaseFAOIUCN status
    Scombridae
    Gasterochisma
    Butterfly mackerelGasterochisma melampus Richardson, 1845164 cm (65 in)50 kg (110 lb)4.4[82] Least concern[83]
    Carangidae
    Jack mackerel
    Atlantic horse mackerelTrachurus trachurus (Linnaeus, 1758)70 cm (28 in)22 cm (8.7 in)2.0 kg (4.4 lb)3.64[84][85]Not assessed
    Blue jack mackerelT. picturatus (Bowdich, 1825)60 cm (24 in)25 cm (9.8 in)18 years3.32[86] Data deficient[87]
    Cape horse mackerelT. capensis (Castelnau, 1861)60 cm (24 in)30 cm (12 in)3.47[88][89]Not assessed[90]
    Chilean jack mackerelT. murphyi (Nichols, 1920)70 cm (28 in)45 cm (18 in)16 years3.49[91][92] Data deficient[87]
    Cunene horse mackerelT. trecae (Cadenat, 1950)35 cm (14 in)2.0 kg (4.4 lb)3.49[93][94]Not assessed
    Greenback horse mackerelT. declivis (Jenyns, 1841)64 cm (25 in)42 cm (17 in)25 years3.93[95][96]Not assessed[97]
    Japanese horse mackerelT. japonicus (Temminck & Schlegel, 1844)50 cm (20 in)35 cm (14 in)0.66 kg (1.5 lb)12 years3.4[98][99]Not assessed
    Mediterranean horse mackerelT. mediterraneus (Steindachner, 1868)60 cm (24 in)30 cm (12 in)3.59[100][101]Not assessed
    Pacific jack mackerelT. symmetricus (Ayres, 1855)81 cm (32 in)55 cm (22 in)30 years3.56[102] Least concern[103]
    Yellowtail horse mackerelT. novaezelandiae (Richardson, 1843)50 cm (20 in)35 cm (14 in)25 years4.5[104]Not assessed
    Gempylidae
    Snake mackerel
    Black snake mackerelNealotus tripes (Johnson, 1865)25 cm (9.8 in)15 cm (5.9 in)4.2[105]Not assessed
    Blacksail snake mackerelThyrsitoides marleyi (Fowler, 1929)200 cm (79 in)100 cm (39 in)4.19[106]Not assessed
    Snake mackerelGempylus serpens (Cuvier, 1829)100 cm (39 in)60 cm (24 in)4.35[107]Not assessed
    Violet snake mackerelNesiarchus nasutus (Johnson, 1862)130 cm (51 in)80 cm (31 in)4.33[108]Not assessed
    White snake mackerelThyrsitops lepidopoides (Cuvier, 1832)40 cm (16 in)25 cm (9.8 in)3.86[109]Not assessed
    HexagrammidaeOkhotsk atka mackerelPleurogrammus azonus (Jordan & Metz, 1913)62 cm (24 in)1.6 kg (3.5 lb)12 years3.58[110][111]Not assessed
    Atka mackerelP. monopterygius (Pallas, 1810)56.5 cm (22.2 in)2.0 kg (4.4 lb)14 years3.33[112]Not assessed
    Still life with mackerel, lemon and tomato, Van Gogh, 1886

    The term “mackerel” is also used as a modifier in the common names of other fish, sometimes indicating the fish has vertical stripes similar to a scombroid mackerel:

    By extension, the term is applied also to other species such as the mackerel tabby cat,[113] and to inanimate objects such as the altocumulus mackerel sky cloud formation.[114][115]

    Characteristics

    [edit]

    Like other scombroids, mackerel such as this Atlantic mackerel are superb swimmers, and can retract their fins into grooves on their bodies for streamlining. They have deeply forked tails and are smaller and slimmer than tuna.[116][117]

    Most mackerel belong to the family Scombridae, which also includes tuna and bonito. Generally, mackerel are much smaller and slimmer than tuna, though in other respects, they share many common characteristics. Their scales, if present at all, are extremely small. Like tuna and bonito, mackerel are voracious feeders, and are swift and manoeuvrable swimmers, able to streamline themselves by retracting their fins into grooves on their bodies. Like other scombroids, their bodies are cylindrical with numerous finlets on the dorsal and ventral sides behind the dorsal and anal fins, but unlike the deep-bodied tuna, they are slim.[116]

    The type species for scombroid mackerels is the Atlantic mackerel, Scomber scombrus. These fish are iridescent blue-green above with a silvery underbelly and near-vertical wavy black stripes running along their upper bodies.[28][118][failed verification]

    The prominent stripes on the back of mackerels seemingly are there to provide camouflage against broken backgrounds. That is not the case, though, because mackerel live in midwater pelagic environments which have no background.[119] However, fish have an optokinetic reflex in their visual systems that can be sensitive to moving stripes.[120] For fish to school efficiently, they need feedback mechanisms that help them align themselves with adjacent fish, and match their speed. The stripes on neighbouring fish provide “schooling marks”, which signal changes in relative position.[119][121]

    Mackerel, such as these Pacific jack mackerel, usually have vertical stripes on their sides which provide “schooling marks”, visual clues that help them stay in formation as they school.[119]

    A layer of thin, reflecting platelets is seen on some of the mackerel stripes. In 1998, E J Denton and D M Rowe argued that these platelets transmit additional information to other fish about how a given fish moves. As the orientation of the fish changes relative to another fish, the amount of light reflected to the second fish by this layer also changes. This sensitivity to orientation gives the mackerel “considerable advantages in being able to react quickly while schooling and feeding.”[122]

    Mackerel range in size from small forage fish to larger game fish. Coastal mackerel tend to be small.[123] The king mackerel is an example of a larger mackerel. Most fish are cold-blooded, but exceptions exist. Certain species of fish maintain elevated body temperatures. Endothermic bony fishes are all in the suborder Scombroidei and include the butterfly mackerel, a species of primitive mackerel.[124]

    Mackerel are strong swimmers. Known in the latin family as “punctualis piscis” which translates to “punctual fish.” This is due to its punctuality of migration during mating season as it moves from warm to cold waters. Atlantic mackerel can swim at a sustained speed of 0.98 m/sec with a burst speed of 5.5 m/sec,[125][126] while chub mackerel can swim at a sustained speed of 0.92 m/sec with a burst speed of 2.25 m/sec.[116]

    Distribution

    [edit]

    King mackerels (Scomberomorus cavalla) cruise on long migrations at 10 kilometres per hour (6.2 mph).[127][128]

    Most mackerel species have restricted distribution ranges.[116]

    In combination, these fish can be found worldwide in all oceans of the world, with the Atlantic chub mackerel being spotted Greenland on rare occasions.

    Some mackerel species migrate vertically. Adult snake mackerel conduct a diel vertical migration, staying in deeper water during the day and rising to the surface at night to feed. The young and juveniles also migrate vertically, but in the opposite direction, staying near the surface during the day and moving deeper at night.[129]

    Lifecycle

    [edit]

    Gannets and other seabirds fuel themselves with mackerel

    Mackerel are prolific broadcast spawners, and must breed near the surface of the water because the eggs of the females float. Individual females lay between 300,000 and 1,500,000 eggs.[116] Their eggs and larvae are pelagic, that is, they float free in the open sea. The larvae and juvenile mackerel feed on zooplankton. As adults, they have sharp teeth, and hunt small crustaceans such as copepodsforage fishshrimp, and squid. In turn, they are hunted by larger pelagic animals such as tuna, billfish, sea lions, sharks, and pelicans.[26][43][130]

    Off Madagascar, spinner sharks follow migrating schools of mackerel.[131] Bryde’s whales feed on mackerel when they can find them. They use several feeding methods, including skimming the surfacelunging, and bubble nets.[132]

    Fisheries

    [edit]

    Global capture of mackerel in tonnes reported by the FAO 1950–2009

    ↑  Scombroid mackerels[1]

    ↑  Non-scombroid mackerels[1]

    Main commercial species

    The chub mackerel is the most intensively fished mackerel in the scombroid family.

    Chilean jack mackerel have been overfished and the population may be in danger of collapsing. Here an entire school of about 400 tons is encircled by a purse seiner.

    A fresh catch from an African beach

    Chub mackerel, Scomber japonicus, are the most intensively fished scombroid mackerel. They account for about half the total capture production of scombroid mackerels.[1] As a species, they are easily confused with Atlantic mackerel. Chub mackerel migrate long distances in oceans and across the Mediterranean. They can be caught with drift nets and suitable trawls, but are most usually caught with surround nets at night by attracting them with lampara lamps.[133]

    The remaining catch of scombroid mackerels is divided equally between the Atlantic mackerel and all other scombroid mackerels. Just these two species (Chub mackerel and Atlantic mackerel) account for about 75% of the total catch of scombroid mackerels.[1]

    Chilean jack mackerel are the most commonly fished nonscombroid mackerel, fished as heavily as chub mackerel.[1][92] The species has been overfished, and its fishery may now be in danger of collapsing.[134][135]

    Smaller mackerel behave like herrings, and are captured in similar ways.[136] Fish species like these, which school near the surface, can be caught efficiently by purse seining. Huge purse-seine vessels use spotter planes to locate the schooling fish. Then they close in using sophisticated sonar to track the shape of the school, which is then encircled with fast auxiliary boats that deploy purse seines as they speed around the school.[137][138]

    Suitably designed trollers can also catch mackerels effectively when they swim near the surface. Trollers typically have several long booms which they lift and drop with “topping lifts”. They haul their lines with electric or hydraulic reels.[139] Fish aggregating devices are also used to target mackerel.[140]

    show  Images and videos                                

    Management

    [edit]

    The North Sea has been overfished to the point where the ecological balance has become disrupted and many jobs in the fishing industry have been lost.[141]

    The Southeast US region spans the Gulf of Mexico, the Caribbean Sea, and the US Southeast Atlantic. Overfishing of king and Spanish mackerel occurred in the 1980s. Regulations were introduced to restrict the size, fishing locations, and bag limits for recreational fishers and commercial fishers. Gillnets were banned in waters off Florida. By 2001, the mackerel stocks had bounced back.[142]

    As food

    [edit]

    Atlantic mackerel on ice at a fish store
    Three freshly caught and gutted Mackerel from Mount’s Bay in Cornwall

    Main article: Mackerel as food

    Mackerel is an important food fish that is consumed worldwide.[143] As an oily fish, it is a rich source of omega-3 fatty acids.[144] The flesh of mackerel spoils quickly, especially in the tropics, and can cause scombroid food poisoning. Accordingly, it should be eaten on the day of capture, unless properly refrigerated or cured.[145]

    Mackerel preservation is not simple. Before the 19th-century development of canning and the widespread availability of refrigeration, salting and smoking were the principal preservation methods available.[146] Historically in England, this fish was not preserved, but was consumed only in its fresh form. However, spoilage was common, leading the authors of The Cambridge Economic History of Europe to remark: “There are more references to stinking mackerel in English literature than to any other fish!”[136] In France, mackerel was traditionally pickled with large amounts of salt, which allowed it to be sold widely across the country.[136]

    For many years mackerel was regarded as ‘unclean’ in the UK and other places due to folklore which suggested that the fish fed on the corpses of dead sailors.[147] A 1976 survey of housewives in Britain undertaken by the White Fish Authority indicated a reluctance to departing from buying the traditional staples of cod, haddock or salmon. Less than 10% of the survey’s 1,931 respondents had ever bought mackerel, and only 3% did so regularly. As a result of this trend, many UK fishmongers during the 1970s did not display or even stock mackerel.[147]

  • Cod 

    Cod (pl.: cod) is the common name for the demersal fish genus Gadus, belonging to the family Gadidae.[1] Cod is also used as part of the common name for a number of other fish species, and one species that belongs to genus Gadus is commonly not called cod (Alaska pollockGadus chalcogrammus).

    The two most common species of cod are the Atlantic cod (Gadus morhua), which lives in the colder waters and deeper sea regions throughout the North Atlantic, and the Pacific cod (Gadus macrocephalus), which is found in both eastern and western regions of the northern PacificGadus morhua was named by Linnaeus in 1758. (However, G. morhua callarias, a low-salinity, nonmigratory race restricted to parts of the Baltic, was originally described as Gadus callarias by Linnaeus.)

    Cod as food is popular in several parts of the world. It has a mild flavour and a dense, flaky, white flesh. Cod livers are processed to make cod liver oil, a common source of vitamin Avitamin Dvitamin E, and omega-3 fatty acids (EPA and DHA). Young Atlantic cod or haddock prepared in strips for cooking is called scrod. In the United Kingdom, Atlantic cod is one of the most common ingredients in fish and chips, along with haddock and plaice.

    Species

    [edit]

    At various times in the past, taxonomists included many species in the genus Gadus. Most of these are now either classified in other genera, or have been recognized as forms of one of three species. All these species have a number of common names, most of them ending with the word “cod”, whereas other species, as closely related, have other common names (such as pollock and haddock). However, many other, unrelated species also have common names ending with cod. The usage often changes with different localities and at different times.

    Cod in the genus Gadus/True cod

    [edit]

    Three species in the genus Gadus are currently called cod:

    Common nameScientific nameMaximum
    length
    Common
    length
    Maximum
    weight
    Maximum
    age
    Trophic
    level
    Fish
    Base
    FAOITISIUCN status
    Atlantic codGadus morhua Linnaeus1758200 cm100 cm96.0 kg25 years4.4[2][3][4] Vulnerable[5]
    Pacific codGadus macrocephalus Tilesius, 1810119 cmcm22.7 kg18 years4.0[6][7][8]Not assessed
    Greenland codGadus ogac Richardson, 183677.0 cmcmkg12 years3.6[9][10][11]Not assessed

    The fourth species of genus Gadus, Gadus chalcogrammus, is commonly called Alaska pollock or walleye pollock. But there are also less widespread alternative trade names highlighting the fish’s belonging to the cod genus, like snow cod[12][13][14] or bigeye cod.[13]

    [edit]

    Cod forms part of the common name of many other fish no longer classified in the genus Gadus. Many are members of the family Gadidae; others are members of three related families within the order Gadiformes whose names include the word “cod”: the morid codsMoridae (100 or so species); the eel cods, Muraenolepididae (four species); and the Eucla codEuclichthyidae (one species). The tadpole cod family (Ranicipitidae) has now been placed in Gadidae.

    Common nameScientific nameMaximum
    length
    Common
    length
    Maximum
    weight
    Maximum
    age
    Trophic
    level
    Fish
    Base
    FAOITISIUCN status
    Arctic codArctogadus glacialis (Peters, 1872)32.5 cmcmkgyears3.8[15][16]Not assessed
    East Siberian codArctogadus borisovi Dryagin, 193255.6 cmcm1.5 kgyears3.9[17][18]Not assessed
    Eucla codEuclichthys polynemus McCulloch, 192635.0 cm22.5 cmkgyears3.6[19][20]Not assessed
    Common lingMolva molva (Linnaeus1758)200 cm106 cm45.0 kg25 years4.3[21][22][23]Not assessed
    Pelagic codMelanonus gracilis Günther, 187818.7 cmcmkgyears3.5[24][25]Not assessed
    Polar codBoreogadus saida (Lepechin, 1774)40.0 cm25.0 cmkg7 years3.1[26][27][28]Not assessed
    Poor codTrisopterus minutus (Linnaeus, 1758)40.0 cm20.0 cmkg5 years3.8[29][30]Not assessed
    Rock codLotella rhacina (Forster, 1801)50.0 cmcmkgyears3.5[31][32]Not assessed
    Saffron codEleginus gracilis (Tilesius, 1810)55.0 cmcm1.3 kg15 years4.1[33][34][35]Not assessed
    Small-headed codLepidion microcephalus Cowper, 195648.0 cmcmkgyears3.5[36][37]Not assessed
    Tadpole codGuttigadus globosus (Paulin, 1986)18.1 cmcmkg3.5 years[38][39]Not assessed

    Some fish have common names derived from “cod”, such as codlingcodlet, or tomcod. (“Codling” is also used as a name for a young cod.)

    Other species

    [edit]

    Some fish commonly known as cod are unrelated to Gadus. Part of this name confusion is market-driven. Severely shrunken Atlantic cod stocks have led to the marketing of cod replacements using culinary names of the form “x cod”, according to culinary rather than phyletic similarity. The common names for the following species have become well established; note that all inhabit the Southern Hemisphere.

    Perciformes

    [edit]

    Fish of the order Perciformes that are commonly called “cod” include:

    Rock cod, reef cod, and coral cod

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    Almost all coral codreef cod or rock cod are also in order Perciformes. Most are better known as groupers, and belong to the family Serranidae. Others belong to the Nototheniidae. Two exceptions are the Australasian red rock cod, which belongs to a different order (see below), and the fish known simply as the rock cod and as soft cod in New Zealand, Lotella rhacina, which as noted above actually is related to the true cod (it is a morid cod).

    Scorpaeniformes

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    From the order Scorpaeniformes:

    Ophidiiformes

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    The tadpole cod family, Ranicipitidae, and the Eucla cod family, Euclichthyidae, were formerly classified in the order Ophidiiformes, but are now grouped with the Gadiformes.

    Marketed as cod

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    Some fish that do not have “cod” in their names are sometimes sold as cod. Haddock and whiting belong to the same family, the Gadidae, as cod.

    Characteristics

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    The Atlantic codGadus morhua

    Cods of the genus Gadus have three rounded dorsal and two anal fins. The pelvic fins are small, with the first ray extended, and are set under the gill cover (i.e. the throat region), in front of the pectoral fins.[40] The upper jaw extends over the lower jaw, which has a well-developed chin barbel. The eyes are medium-sized, approximately the same as the length of the chin barbel. Cod have a distinct white lateral line running from the gill slit above the pectoral fin, to the base of the caudal or tail fin. The back tends to be a greenish to sandy brown, and shows extensive mottling, especially towards the lighter sides and white belly. Dark brown colouration of the back and sides is not uncommon, especially for individuals that have resided in rocky inshore regions.

    The Atlantic cod can change colour at certain water depths. It has two distinct colour phases: gray-green and reddish brown. Its average weight is 5–12 kilograms (11–26 pounds), but specimens weighing up to 100 kg (220 lb) have been recorded. Pacific cod are smaller than Atlantic cod[2][6] and are darker in colour.

    Distribution

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    Atlantic cod (Gadus morhua) live in the colder waters and deeper sea regions throughout the North Atlantic. Pacific cod (Gadus macrocephalus) is found in both eastern and western regions of the Pacific.[41]

    Atlantic cod could be further divided into several stocks, including the Arcto-NorwegianNorth SeaBaltic SeaFaroeIcelandEast GreenlandWest GreenlandNewfoundland, and Labrador stocks. There seems to be little interchange between the stocks, although migrations to their individual breeding grounds may involve distances of 300 kilometres (190 statute miles; 160 nautical miles) or more.[42] For instance, eastern Baltic cod shows specific reproductive adaptations to low salinity compared to Western Baltic and Atlantic cod.[43]

    Atlantic cod occupy varied habitats, favouring rough ground, especially inshore, and are demersal in depths between 6 and 60 metres (20 and 200 feet; 3 and 30 fathoms), 80 m (260 ft; 44 fathoms) on average, although not uncommonly to depths of 600 m (2,000 ft; 330 fathoms). Off the Norwegian and New England coasts and on the Grand Banks of Newfoundland, cod congregate at certain seasons in water of 30–70 m (100–200 ft; 20–40 fathoms) depth. Cod are gregarious and form schools, although shoaling tends to be a feature of the spawning season.

    Life cycle

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    Spawning of northeastern Atlantic cod occurs between January and April (March and April are the peak months), at a depth of 200 metres (660 ft) in specific spawning grounds at water temperatures between 4 and 6 °C (39 and 43 °F). Around the UK, the major spawning grounds are in the middle to southern North Sea, the start of the Bristol Channel (north of Newquay), the Irish Channel (both east and west of the Isle of Man), around Stornoway, and east of Helmsdale.

    Prespawning courtship involves fin displays and male grunting, which leads to pairing.[44] The male inverts himself beneath the female, and the pair swim in circles while spawning. The eggs are planktonic and hatch between eight and 23 days, with larva reaching 4 millimetres (532 inch) in length. This planktonic phase lasts some ten weeks, enabling the young cod to increase its body weight by 40-fold, and growing to about 2 cm (34 in). The young cod then move to the seabed and change their diet to small benthic crustaceans, such as isopods and small crabs. They increase in size to 8 cm (3 in) in the first six months, 14–18 cm (5+12–7 in) by the end of their first year, and to 25–35 cm (10–14 in) by the end of the second. Growth tends to be less at higher latitudes. Cod reach maturity at about 50 cm (20 in) at about 3 to 4 years of age. Changes in growth rate over decades of particular stocks have been reported, current eastern Baltic cod shows the lowest growth observed since 1955.[45]

    Ecology

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    See also: Diseases and parasites in cod

    A fish with its gills infested with two cod worms

    Adult cod are active hunters, feeding on sand eelswhitinghaddock, small cod, squidcrabslobstersmusselswormsmackerel, and molluscs.

    In the Baltic Sea the most important prey species are herring and sprat.[46] Many studies that analyze the stomach contents of these fish indicate that cod is the top predator, preying on the herring and sprat.[46] Sprat form particularly high concentrations in the Bornholm Basin in the southern Baltic Sea.[47] Although cod feed primarily on adult sprat, sprat tend to prey on the cod eggs and larvae.[48]

    Cod and related species are plagued by parasites. For example, the cod wormLernaeocera branchialis, starts life as a copepod-like larva, a small free-swimming crustacean. The first host used by the larva is a flatfish or lumpsucker, which it captures with grasping hooks at the front of its body. It penetrates the fish with a thin filament, which it uses to suck the fish’s blood. The nourished larvae then mate on the fish.[49][50] The female larva, with her now fertilized eggs, then finds a cod, or a cod-like fish such as a haddock or whiting. There the larva clings to the gills while it metamorphoses into a plump sinusoidal wormlike body with a coiled mass of egg strings at the rear. The front part of the worm’s body penetrates the body of the cod until it enters the rear bulb of the host’s heart. There, firmly rooted in the cod’s circulatory system, the front part of the parasite develops like the branches of a tree, reaching into the main artery. In this way, the worm extracts nutrients from the cod’s blood, remaining safely tucked beneath the cod’s gill cover until it releases a new generation of offspring into the water.[49][50]

    Fisheries

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    Global commercial capture of Atlantic and Pacific cod
    in million tonnes reported by the FAO 1950–2010[51]

    The same chart as above, but showing embedded in light green, the collapse of the Atlantic northwest cod fishery[52]

    Main article: Cod fisheries

    This section needs to be updated. Please help update this article to reflect recent events or newly available information. (October 2022)

    The 2006 northwest Atlantic cod quota is 23,000 tons, representing half the available stocks, while the northeast Atlantic quota is 473,000 tons. Pacific cod is currently enjoying strong global demand. The 2006 total allowable catch (TAC) for the Gulf of Alaska and Aleutian Islands was 260,000 tons.[53]

    Aquaculture

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    Farming of Atlantic cod has received a significant amount of interest due to the overall trend of increasing cod prices alongside reduced wild catches.[54] However, progress in creating large scale farming of cod has been slow, mainly due to bottlenecks in the larval production stage, where survival and growth are often unpredictable.[55] It has been suggested that this bottleneck may be overcome by ensuring cod larvae are fed diets with similar nutritional content as the copepods they feed on in the wild [56][57] Recent examples have shown that increasing dietary levels of minerals such as selenium, iodine and zinc may improve survival and/or biomarkers for health in aquaculture reared cod larvae.[58][59][60][61]

    As food

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    Main article: Cod as food

    Preserved codfish

    Cod is popular as a food with a mild flavour and a dense, flaky white flesh. Cod livers are processed to make cod liver oil, an important source of vitamin Avitamin Dvitamin E and omega-3 fatty acids (EPA and DHA).

    Young Atlantic cod or haddock prepared in strips for cooking is called scrod. In the United KingdomAtlantic cod is one of the most common ingredients in fish and chips, along with haddock and plaice. Cod’s soft liver can be tinned (canned) and eaten.

    History

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    Sixteenth-century Flemish fishmonger displaying cod, by Joachim Beuckelaer

    Cod has been an important economic commodity in international markets since the Viking period (around 800 AD). Norwegians travelled with dried cod and soon a dried cod market developed in southern Europe. This market has lasted for more than 1,000 years, enduring the Black Death, wars and other crises, and is still an important Norwegian fish trade.[62] The Portuguese began fishing cod in the 15th century. Clipfish is widely enjoyed in Portugal. The Basques played an important role in the cod trade, and allegedly found the Canadian fishing banks before Columbus‘ discovery of America.[63] The North American east coast developed in part due to the vast cod stocks. Many cities in the New England area are located near cod fishing grounds. The fish was so important to the history and development of Massachusetts, the state’s House of Representatives hung a wood carving of a codfish, known as the Sacred Cod of Massachusetts, in its chambers.

    Apart from the long history, cod differ from most fish because the fishing grounds are far from population centres. The large cod fisheries along the coast of North Norway (and in particular close to the Lofoten islands) have been developed almost uniquely for export, depending on sea transport of stockfish over large distances.[64] Since the introduction of salt, dried and salted cod (clipfish or ‘klippfisk’ in Norwegian) has also been exported. By the end of the 14th century, the Hanseatic League dominated trade operations and sea transport, with Bergen as the most important port.[65]

    William Pitt the Elder, criticizing the Treaty of Paris in Parliament, claimed cod was “British gold”; and that it was folly to restore Newfoundland fishing rights to the French.

    In the 17th and 18th centuries in the New World, especially in Massachusetts and Newfoundland, cod became a major commodity, creating trade networks and cross-cultural exchanges. In 1733, Britain tried to gain control over trade between New England and the British Caribbean by imposing the Molasses Act, which they believed would eliminate the trade by making it unprofitable. The cod trade grew instead, because the “French were eager to work with the New Englanders in a lucrative contraband arrangement”.[63] In addition to increasing trade, the New England settlers organized into a “codfish aristocracy”. The colonists rose up against Britain’s “tariff on an import”.

    In the 20th century, Iceland re-emerged as a fishing power and entered the Cod Wars. In the late 20th and early 21st centuries, fishing off the European and American coasts severely depleted stocks and become a major political issue. The necessity of restricting catches to allow stocks to recover upset the fishing industry and politicians who are reluctant to hurt employment.

    Collapse of the Atlantic northwest cod fishery

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    Main article: Collapse of the Atlantic northwest cod fishery

    This article’s tone or style may not reflect the encyclopedic tone used on Wikipedia. See Wikipedia’s guide to writing better articles for suggestions. (December 2024) (Learn how and when to remove this message)
    The Atlantic fishery abruptly collapsed in 1992, following overfishing since the late 1950s, and an earlier partial collapse in the 1970s.[66][67]

    On July 2, 1992, the Honourable John Crosbie, Canadian Federal Minister of Fisheries and Oceans, declared a two-year moratorium on the Northern Cod fishery,[68] a designated fishing region off the coast of Newfoundland, after data showed that the total cod biomass had suffered a collapse to less than 1% of its normal value.[69] The minister championed the measure as a temporary solution, allowing the cod population time to recover.[70] The fisheries had long shaped the lives and communities on Canada’s Atlantic eastern coast for the preceding five centuries. Societies which are dependent on fishing have a strong mutual relationship with them: the act of fishing changes the ecosystems’ balance, which forces the fishery and, in turn, the fishing societies to adapt to new ecological conditions.[69]

    The near-complete destruction of the Atlantic northwest cod biomass off the shores devastated coastal communities, which had been overexploiting the same cod population for decades.[70] The fishermen along the Atlantic northwest had employed modern fishing technologies, including the ecologically-devastating practice of trawling, especially in the years leading up to the 1990s, in the misguided belief that fishing stocks are perpetually plentiful and unable to be depleted.[70][71][68] After this assumption was empirically and abruptly shown to be incorrect, to the dismay of government officials and rural workers, some 19,000 fishermen and cod processing plant workers in Newfoundland lost their employment.[70] The powerful economic engine of rural Newfoundland coughed, wheezed, and died. Nearly 40,000 workers and harvesters in the provinces of Newfoundland and Labrador applied for the federal relief program TAGS (the Atlantic Groundfish Strategy). Abandoned and rusting fishing boats still litter the coasts of Newfoundland and the Canadian northwest to this day.[68]

    The fishery minister, John Crosbie, after delivering a speech on the day before the declaration of the moratorium, or July 1, 1992, was publicly heckled and verbally harassed by disgruntled locals at a fishing village.[72] The moratorium, initially lasting for only two years,[70] was indefinitely extended after it became evident that cod populations had not recovered at all but, instead, had continued to spiral downward in both size and numbers, due to the damage caused by decades of horrible fishing practices, and the fact that the moratorium had permitted exceptions for food fisheries for “personal consumption” purposes to this very day.[70] Some 12,000 tons of Northwest cod are still being caught every year along the Newfoundland coast by local fishermen.[68]

    The collapse of the four-million ton biomass, which had persevered through several previous marine extinctions over tens of millions of years, in a timespan of no more than 20 years, is oft-cited by researchers as one of the most visible examples of the phenomenon of the “Tragedy of the Commons.”[70] Factors which had been implicated as contributing to the collapse include: overfishing; government mismanagement; the disregard of scientific uncertainty;[70] warming habitat waters; declining reproduction; and plain human ignorance.[68] The Northern Cod biomass has been recovering slowly since the imposition of the moratorium. However, as of 2021, the growth of the cod population has been stagnant since 2017, and some scientists argue that the population will not rebound unless the Fisheries Department of Canada lower its yearly quota to 5,000 tons.[73]

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