genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

Gadus ''Gadus'' is a genus of demersal fish in the family Gadidae, commonly known as cod, although there are additional cod species in other genera. The best known member of the genus is the Atlantic cod. Species Today, three species in the genus ar ...

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Gadidae The Gadidae are a family of marine fish, included in the order Gadiformes, known as the cods, codfishes, or true cods. It contains several commercially important fishes, including the cod, haddock, whiting, and pollock. Most gadid species ...

Alaska pollock The Alaska pollock or walleye pollock (''Gadus chalcogrammus'') is a marine fish species of the cod genus '' Gadus'' and family Gadidae. It is a semi-pelagic schooling fish widely distributed in the North Pacific, with largest concentrations ...

Atlantic cod The Atlantic cod (''Gadus morhua'') is a benthopelagic fish of the family Gadidae, widely consumed by humans. It is also commercially known as cod or codling.North Atlantic, and the

Pacific cod The Pacific cod (''Gadus macrocephalus)'' is a species of ray-finned fish in the family Gadidae. It is a bottom-dwelling fish found in the northern Pacific Ocean, mainly on the continental shelf and upper slopes, to depths of about . It can gro ...

(''Gadus macrocephalus''), found in both eastern and western regions of the northern

Pacific The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the contine ...

. ''Gadus morhua'' was named by

Linnaeus Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his ennoblement in 1761 as Carl von Linné Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalised binomial nomenclature, the ...

in 1758. (However, ''G. morhua callarias'', a low-salinity, nonmigratory

race Race, RACE or "The Race" may refer to: * Race (biology), an informal taxonomic classification within a species, generally within a sub-species * Race (human categorization), classification of humans into groups based on physical traits, and/or s ...

restricted to parts of the Baltic, was originally described as ''Gadus callarias'' by Linnaeus.) 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 Cod liver oil is a dietary supplement derived from liver of cod fish (Gadidae). As with most fish oils, it contains the omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), and also vitamin A and vitamin D. Histori ...

, a common source of

vitamin A Vitamin A is a fat-soluble vitamin and an essential nutrient for humans. It is a group of organic compounds that includes retinol, retinal (also known as retinaldehyde), retinoic acid, and several provitamin A carotenoids (most notably ...

,

vitamin D Vitamin D is a group of fat-soluble secosteroids responsible for increasing intestinal absorption of calcium, magnesium, and phosphate, and many other biological effects. In humans, the most important compounds in this group are vitamin D3 (c ...

,

vitamin E Vitamin E is a group of eight fat soluble compounds that include four tocopherols and four tocotrienols. Vitamin E deficiency, which is rare and usually due to an underlying problem with digesting dietary fat rather than from a diet low in vi ...

, and

omega-3 fatty acid Omega−3 fatty acids, also called Omega-3 oils, ω−3 fatty acids or ''n''−3 fatty acids, are polyunsaturated fatty acids (PUFAs) characterized by the presence of a double bond, three atoms away from the terminal methyl group in their chem ...

s (

EPA The Environmental Protection Agency (EPA) is an independent executive agency of the United States federal government tasked with environmental protection matters. President Richard Nixon proposed the establishment of EPA on July 9, 1970; it be ...

and

DHA DHA, Dha and dha may refer to: Chemicals * Docosahexaenoic acid, a 22:6 omega-3 fatty acid * Dehydroandrosterone, an endogenous androgenic steroid * Dehydroascorbic acid, an oxidized form of ascorbic acid * Dehydroacetic acid, a pyrone derivati ...

). Young Atlantic cod or

haddock The haddock (''Melanogrammus aeglefinus'') is a saltwater ray-finned fish from the family Gadidae, the true cods. It is the only species in the monotypic genus ''Melanogrammus''. It is found in the North Atlantic Ocean and associated seas wher ...

prepared in strips for cooking is called

scrod Scrod or schrod () is a small cod or haddock, and sometimes other whitefish (fisheries term), whitefish, used as food. It is usually served as a fish fillet, fillet, though formerly it was often split instead. In the wholesale fish business, scro ...

. In the United Kingdom,

Atlantic cod The Atlantic cod (''Gadus morhua'') is a benthopelagic fish of the family Gadidae, widely consumed by humans. It is also commercially known as cod or codling.fish and chips, along with

haddock The haddock (''Melanogrammus aeglefinus'') is a saltwater ray-finned fish from the family Gadidae, the true cods. It is the only species in the monotypic genus ''Melanogrammus''. It is found in the North Atlantic Ocean and associated seas wher ...

and

plaice Plaice is a common name for a group of flatfish that comprises four species: the European, American, Alaskan and scale-eye plaice. Commercially, the most important plaice is the European. The principal commercial flatfish in Europe, it is al ...

.

Species

At various times in the past, taxonomists included many species in the genus ''

Gadus ''Gadus'' is a genus of demersal fish in the family Gadidae, commonly known as cod, although there are additional cod species in other genera. The best known member of the genus is the Atlantic cod. Species Today, three species in the genus ar ...

''. 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 Pollock or pollack (pronounced ) is the common name used for either of the two species of North Atlantic marine fish in the genus ''Pollachius''. '' Pollachius pollachius'' is referred to as pollock in North America, Ireland and the United Kingd ...

and

haddock The haddock (''Melanogrammus aeglefinus'') is a saltwater ray-finned fish from the family Gadidae, the true cods. It is the only species in the monotypic genus ''Melanogrammus''. It is found in the North Atlantic Ocean and associated seas wher ...

). 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''

Three species in the genus ''Gadus'' are currently called cod: 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''SeafoodSource.com (23 January 2014):
Alaska pollock
''. or ''bigeye cod''.

Related species

''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 The Gadidae are a family of marine fish, included in the order Gadiformes, known as the cods, codfishes, or true cods. It contains several commercially important fishes, including the cod, haddock, whiting, and pollock. Most gadid species ...

; others are members of three related families within the order

Gadiformes Gadiformes are an order of ray-finned fish, also called the Anacanthini, that includes the cod. Many major food fish are in this order. They are found in marine waters throughout the world and the vast majority of the species are found in tempe ...

whose names include the word "cod": the

morid cod The Moridae are a family of cod-like fishes, known as codlings, hakelings, and moras. Morids are marine fishes found throughout the world, and may be found at depths to , although most prefer shallower waters. In appearance, they greatly resemb ...

s,

Moridae The Moridae are a family of cod-like fishes, known as codlings, hakelings, and moras. Morids are marine fishes found throughout the world, and may be found at depths to , although most prefer shallower waters. In appearance, they greatly resemb ...

(100 or so species); the eel cods,

Muraenolepididae The Muraenolepididae is a family of cod-like fish, known as eel cods, found in southern oceans. References Gadiformes {{Gadiformes-stub ...

(four species); and the Eucla cod,

Euclichthyidae The Eucla cod (''Euclichthys polynemus'') is a deepwater marine fish belonging to the cod order ( Gadiformes). It is the only species currently classified in the family Euclichthyidae. It is named after the town of Eucla, Western Australia, in ...

(one species). The tadpole cod family (

Ranicipitidae The Gadidae are a family of marine fish, included in the order Gadiformes, known as the cods, codfishes, or true cods. It contains several commercially important fishes, including the cod, haddock, whiting, and pollock. Most gadid species are ...

) has now been placed in Gadidae. Some fish have common names derived from "cod", such as codling,

codlet Codlets are a family, Bregmacerotidae, of cod-like fishes, containing the single genus ''Bregmaceros'' found in tropical and subtropical waters throughout the world. They are very small fishes and even the largest, ''B. lanceolatus'', reaches on ...

, or

tomcod ''Microgadus tomcod'', also commonly known as frostfish, Atlantic tomcod or winter cod, is a type of cod found in North American coastal waters from the Gulf of St. Lawrence, St. Lawrence River and northern Newfoundland, south to Virginia. T ...

. ("Codling" is also used as a name for a young cod.)

Other species

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 name Culinary names, menu names, or kitchen names are names of foods used in the preparation or selling of food, as opposed to their names in agriculture or in scientific nomenclature. The menu name may even be different from the kitchen name. For ex ...

s 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

Fish of the order

Perciformes Perciformes (), also called the Percomorpha or Acanthopteri, is an order or superorder of ray-finned fish. If considered a single order, they are the most numerous order of vertebrates, containing about 41% of all bony fish. Perciformes means ...

that are commonly called "cod" include: *

Blue cod The New Zealand blue cod (''Parapercis colias'') is a temperate marine fish of the family Pinguipedidae. It is also known variously as Boston blue cod, New Zealand cod, sand perch, or its Māori names rāwaru, pākirikiri and patutuki. It is ...

''Parapercis colias'' *

Eastern freshwater cod The eastern freshwater cod (''Maccullochella ikei''), also known as the eastern cod or Clarence River cod, is a large predatory freshwater fish of the genus ''Maccullochella'' and the family Percichthyidae, that occur in the coastal Clarence Rive ...

''Maccullochella ikei'' *

Mary River cod The Mary River cod (''Maccullochella mariensis'') is a species of temperate perch native to the coastal Mary River system of southern Queensland, Australia. Mary River cod are one of Australia's most endangered freshwater fishes and are notab ...

''Maccullochella peelii mariensis'' * Murray cod ''Maccullochella peelii peelii'' *

Potato cod The potato grouper (''Epinephelus tukula''), also called the potato cod or potato bass, is a species of marine ray-finned fish, a grouper from the subfamily Epinephelinae which is part of the family Serranidae, which also includes the anthias a ...

''Epinephelus tukula'' *

Sleepy cod The sleepy cod (''Oxyeleotris lineolata'') is a medium-sized fish in the family Butidae, native to tropical fresh waters of northern Australia and questionably from New Guinea. It is a member of the order Perciformes, thus is unrelated to the ...

''Oxyeleotris lineolatus'' *

Trout cod The trout cod (''Maccullochella macquariensis'') or bluenose cod, is a large predatory freshwater fish of the genus ''Maccullochella'' and the family Percichthyidae, closely related to the Murray cod. It was originally widespread in the south ...

''Maccullochella macquariensis'' *The notothen family,

Nototheniidae : ''In some scientific literature, the term "cod icefish" is used to identify members of this family. This should not be confused with the term "icefish," which refers to the "white-blooded" fishes of the family Channichthyidae. See Icefish (disam ...

, including: **

Antarctic cod The Antarctic toothfish (''Dissostichus mawsoni'') is a large, black or brown fish found in very cold (subzero) waters of the Southern Ocean near Antarctica. It is the largest fish in the Southern Ocean, feeding on shrimp and smaller fish, and pr ...

''Dissostichus mawsoni'' ** Black cod ''Notothenia microlepidota'' ** Maori cod ''Paranotothenia magellanica''

Rock cod, reef cod, and coral cod

Almost all coral cod,

reef cod A reef is a ridge or shoal of rock, coral or similar relatively stable material, lying beneath the surface of a natural body of water. Many reefs result from natural, abiotic component, abiotic processes—deposition (geology), deposition of ...

or rock cod are also in order

Perciformes Perciformes (), also called the Percomorpha or Acanthopteri, is an order or superorder of ray-finned fish. If considered a single order, they are the most numerous order of vertebrates, containing about 41% of all bony fish. Perciformes means ...

. Most are better known as

grouper Groupers are fish of any of a number of genera in the subfamily Epinephelinae of the family Serranidae, in the order Perciformes. Not all serranids are called "groupers"; the family also includes the sea basses. The common name "grouper" is ...

s, and belong to the family

Serranidae The Serranidae are a large family of fishes belonging to the order Perciformes. The family contains about 450 species in 65 genera, including the sea basses and the groupers (subfamily Epinephelinae). Although many species are small, in some ca ...

. Others belong to the

Nototheniidae : ''In some scientific literature, the term "cod icefish" is used to identify members of this family. This should not be confused with the term "icefish," which refers to the "white-blooded" fishes of the family Channichthyidae. See Icefish (disam ...

. Two exceptions are the

Australasia Australasia is a region that comprises Australia, New Zealand and some neighbouring islands in the Pacific Ocean. The term is used in a number of different contexts, including geopolitically, physiogeographically, philologically, and ecologi ...

n

red rock cod ''Scorpaena papillosa'', the red rock cod, Southern red scorpionfish, chained scorpionfish, common red gurnard, Southern red scorpioncod, Southern rockcod or dwarf scorpionfish, is a species of venomous marine ray-finned fish belonging to the fam ...

, which belongs to a different order (see below), and the fish known simply as the rock cod and as

soft cod Soft may refer to: * Softness, or hardness, a property of physical materials Arts and entertainment * ''Soft!'', a 1988 novel by Rupert Thomson * Soft (band), an American music group * Soft (album), ''Soft'' (album), by Dan Bodan, 2014 * Softs (a ...

in New Zealand, ''

Lotella rhacina The rock cod (''Lotella rhacina'') is a temperate fish found off the coasts of southeastern Australia, Tasmania, the Great Australian Bight and northwards up the southwestern Australia coasts. They are also found around the coasts of New Zealand ...

'', which as noted above actually is related to the true cod (it is a morid cod).

Scorpaeniformes

From the order

Scorpaeniformes The Scorpaeniformes are a diverse order of ray-finned fish, including the lionfishes and sculpins, but have also been called the Scleroparei. It is one of the five largest orders of bony fishes by number of species, with over 1,320. They are ...

: *

Ling cod The lingcod or ling cod (''Ophiodon elongatus''), also known as the buffalo cod or cultus cod, is a fish of the greenling family Hexagrammidae. It is the only extant member of the genus ''Ophiodon. ''A slightly larger, extinct species, '' Ophi ...

''Ophiodon elongatus'' *

Red rock cod ''Scorpaena papillosa'', the red rock cod, Southern red scorpionfish, chained scorpionfish, common red gurnard, Southern red scorpioncod, Southern rockcod or dwarf scorpionfish, is a species of venomous marine ray-finned fish belonging to the fam ...

''Scorpaena papillosa'' *Rock cod ''

Sebastes ''Sebastes'' is a genus of marine ray-finned fish belonging to the subfamily Sebastinae part of the family Scorpaenidae, most of which have the common name of rockfish. A few are called ocean perch, sea perch or redfish instead. They are found ...

''

Ophidiiformes

The tadpole cod family,

Ranicipitidae The Gadidae are a family of marine fish, included in the order Gadiformes, known as the cods, codfishes, or true cods. It contains several commercially important fishes, including the cod, haddock, whiting, and pollock. Most gadid species are ...

, and the Eucla cod family,

Euclichthyidae The Eucla cod (''Euclichthys polynemus'') is a deepwater marine fish belonging to the cod order ( Gadiformes). It is the only species currently classified in the family Euclichthyidae. It is named after the town of Eucla, Western Australia, in ...

, were formerly classified in the order

Ophidiiformes Ophidiiformes is an order of ray-finned fish that includes the cusk-eels (family Ophidiidae), pearlfishes (family Carapidae), viviparous brotulas (family Bythitidae), and others. Members of this order have small heads and long slender bodies. Th ...

, but are now grouped with the

Gadiformes Gadiformes are an order of ray-finned fish, also called the Anacanthini, that includes the cod. Many major food fish are in this order. They are found in marine waters throughout the world and the vast majority of the species are found in tempe ...

.

Marketed as cod

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. *

Haddock The haddock (''Melanogrammus aeglefinus'') is a saltwater ray-finned fish from the family Gadidae, the true cods. It is the only species in the monotypic genus ''Melanogrammus''. It is found in the North Atlantic Ocean and associated seas wher ...

''Melanogrammus aeglefinus'' * Whiting ''Merlangius merlangus'' *

Patagonian toothfish The Patagonian toothfish (''Dissostichus eleginoides'') is a species of notothen found in cold waters () between depths of in the southern Atlantic, Pacific, and Indian Oceans and Southern Ocean on seamounts and continental shelves around most ...

or Chilean seabass

Characteristics

Cods of the genus ''Gadus'' have three rounded

dorsal Dorsal (from Latin ''dorsum'' ‘back’) may refer to: * Dorsal (anatomy), an anatomical term of location referring to the back or upper side of an organism or parts of an organism * Dorsal, positioned on top of an aircraft's fuselage * Dorsal c ...

and two anal fins. The pelvic fins are small, with the first ray extended, and are set under the

gill A gill () is a respiratory organ that many aquatic organisms use to extract dissolved oxygen from water and to excrete carbon dioxide. The gills of some species, such as hermit crabs, have adapted to allow respiration on land provided they are ...

cover (i.e. the throat region), in front of the

pectoral fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as ...

s. 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 The Atlantic cod (''Gadus morhua'') is a benthopelagic fish of the family Gadidae, widely consumed by humans. It is also commercially known as cod or codling.Atlantic cod The Atlantic cod (''Gadus morhua'') is a benthopelagic fish of the family Gadidae, widely consumed by humans. It is also commercially known as cod or codling.Pacific The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the contine ...

."Cod"
, ''Encyclopædia Britannica online'' 2008 Atlantic cod divide into several stocks, including the Arcto-Norwegian,

North Sea The North Sea lies between Great Britain, Norway, Denmark, Germany, the Netherlands and Belgium. An epeiric sea, epeiric sea on the European continental shelf, it connects to the Atlantic Ocean through the English Channel in the south and the ...

,

Baltic Sea The Baltic Sea is an arm of the Atlantic Ocean that is enclosed by Denmark, Estonia, Finland, Germany, Latvia, Lithuania, Poland, Russia, Sweden and the North and Central European Plain. The sea stretches from 53°N to 66°N latitude and ...

, Faroe,

Iceland Iceland ( is, Ísland; ) is a Nordic island country in the North Atlantic Ocean and in the Arctic Ocean. Iceland is the most sparsely populated country in Europe. Iceland's capital and largest city is Reykjavík, which (along with its s ...

,

East Greenland Tunu, originally Østgrønland ("East Greenland"), was one of the three counties (''amter'') of Greenland until 31 December 2008. The county seat was at the main settlement, Tasiilaq. The county's population in 2005 was around 3,800. The county ...

,

West Greenland Kitaa, originally Vestgrønland ("West Greenland"), is a former administrative division of Greenland. It was by far the most populated of the divisions, being home to almost 90% of the total population. The divisions were de facto replaced by st ...

, Newfoundland, and

Labrador , nickname = "The Big Land" , etymology = , subdivision_type = Country , subdivision_name = Canada , subdivision_type1 = Province , subdivision_name1 ...

stocks. There seems to be little interchange between the stocks, although migrations to their individual breeding grounds may involve distances of or more. For instance, eastern Baltic cod shows specific reproductive adaptations to low salinity compared to Western Baltic and Atlantic cod. Atlantic cod occupy varied habitat, favouring rough ground, especially inshore, and are demersal in depths between , on average, although not uncommonly to depths of . Off the Norwegian and New England coasts and on the

Grand Banks of Newfoundland The Grand Banks of Newfoundland are a series of underwater plateaus south-east of the island of Newfoundland on the North American continental shelf. The Grand Banks are one of the world's richest fishing grounds, supporting Atlantic cod, swordf ...

, cod congregate at certain seasons in water of depth. Cod are gregarious and form schools, although

shoaling In biology, any group of fish that stay together for social reasons are shoaling, and if the group is swimming in the same direction in a coordinated manner, they are schooling. In common usage, the terms are sometimes used rather loosely. Ab ...

tends to be a feature of the spawning season.

Life cycle

Spawning of northeastern Atlantic cod occurs between January and April (March and April are the peak months), at a depth of in specific spawning grounds at water temperatures between . Around the UK, the major spawning grounds are in the middle to southern North Sea, the start of the Bristol Channel (north of

Newquay Newquay ( ; kw, Tewynblustri) is a town on the north coast in Cornwall, in the south west of England. It is a civil parish, seaside resort, regional centre for aerospace industries, spaceport and a fishing port on the North Atlantic coast of ...

), the Irish Channel (both east and west of the

Isle of Man ) , anthem = "O Land of Our Birth" , image = Isle of Man by Sentinel-2.jpg , image_map = Europe-Isle_of_Man.svg , mapsize = , map_alt = Location of the Isle of Man in Europe , map_caption = Location of the Isle of Man (green) in Europe ...

), around Stornoway, and east of

Helmsdale Helmsdale ( sco, Helmsdal, gd, Bun Ilidh) is a village on the east coast of Sutherland, in the Highland council area of Scotland. The modern village was planned in 1814 to resettle communities that had been removed from the surrounding straths ...

. Prespawning courtship involves fin displays and male grunting, which leads to pairing. 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 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 . The young cod then move to the seabed and change their diet to small benthic

crustaceans Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean gro ...

, such as

isopods Isopoda is an order of crustaceans that includes woodlice and their relatives. Isopods live in the sea, in fresh water, or on land. All have rigid, segmented exoskeletons, two pairs of antennae, seven pairs of jointed limbs on the thorax, and ...

and small crabs. They increase in size to in the first six months, by the end of their first year, and to by the end of the second. Growth tends to be less at higher latitudes. Cod reach maturity at about 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.

Ecology

Adult cod are active hunters, feeding on

sand eel Sand eel or sandeel is the common name used for a considerable number of species of fish. While they are not true eels, they are eel-like in their appearance and can grow up to in length. Many species are found off the western coasts of Europe ...

s, whiting,

haddock The haddock (''Melanogrammus aeglefinus'') is a saltwater ray-finned fish from the family Gadidae, the true cods. It is the only species in the monotypic genus ''Melanogrammus''. It is found in the North Atlantic Ocean and associated seas wher ...

, small cod, squid, crabs, lobsters, mussels,

worm Worms are many different distantly related bilateral animals that typically have a long cylindrical tube-like body, no limbs, and no eyes (though not always). Worms vary in size from microscopic to over in length for marine polychaete wo ...

s, mackerel, and molluscs. In the Baltic Sea the most important prey species are herring and

sprat Sprat is the common name applied to a group of forage fish belonging to the genus '' Sprattus'' in the family Clupeidae. The term also is applied to a number of other small sprat-like forage fish ('' Clupeoides'', '' Clupeonella'', '' Corica'' ...

. Many studies that analyze the stomach contents of these fish indicate that cod is the top predator, preying on the herring and sprat. Sprat form particularly high concentrations in the Bornholm Basin in the southern Baltic Sea. Although cod feed primarily on adult sprat, sprat tend to prey on the cod eggs and larvae. Cod and related species are plagued by parasites. For example, the cod worm, ''Lernaeocera 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. The female larva, with her now fertilized eggs, then finds a cod, or a cod-like fish such as a

haddock The haddock (''Melanogrammus aeglefinus'') is a saltwater ray-finned fish from the family Gadidae, the true cods. It is the only species in the monotypic genus ''Melanogrammus''. It is found in the North Atlantic Ocean and associated seas wher ...

or whiting. There the larva clings to the

gill A gill () is a respiratory organ that many aquatic organisms use to extract dissolved oxygen from water and to excrete carbon dioxide. The gills of some species, such as hermit crabs, have adapted to allow respiration on land provided they are ...

s 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 The heart is a muscular organ in most animals. This organ pumps blood through the blood vessels of the circulatory system. The pumped blood carries oxygen and nutrients to the body, while carrying metabolic waste such as carbon dioxide to t ...

. 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 An artery (plural arteries) () is a blood vessel in humans and most animals that takes blood away from the heart to one or more parts of the body (tissues, lungs, brain etc.). Most arteries carry oxygenated blood; the two exceptions are the pu ...

. 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.

Fisheries

The 2006 northwest Atlantic cod

quota Quota may refer to: Economics * Import quota, a trade restriction on the quantity of goods imported into a country * Market Sharing Quota, an economic system used in Canadian agriculture * Milk quota, a quota on milk production in Europe * Indi ...

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 The Common Fisheries Policy (CFP) is the fisheries policy of the European Union (EU). It sets quotas for which member states are allowed to catch each type of fish, as well as encouraging the fishing industry by various market interventions. I ...

(TAC) for the

Gulf of Alaska The Gulf of Alaska (Tlingit: ''Yéil T'ooch’'') is an arm of the Pacific Ocean defined by the curve of the southern coast of Alaska, stretching from the Alaska Peninsula and Kodiak Island in the west to the Alexander Archipelago in the east ...

and

Aleutian Islands The Aleutian Islands (; ; ale, Unangam Tanangin,”Land of the Aleuts", possibly from Chukchi ''aliat'', "island"), also called the Aleut Islands or Aleutic Islands and known before 1867 as the Catherine Archipelago, are a chain of 14 large v ...

was 260,000 tons.

Aquaculture

Farming of Atlantic cod has received a significant amount of interest due to the overall trend of increasing cod prices alongside reduced wild catches. 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. 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 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.

As food

Cod is popular as a food with a mild flavor and a dense, flaky white flesh. Cod livers are processed to make

cod liver oil Cod liver oil is a dietary supplement derived from liver of cod fish (Gadidae). As with most fish oils, it contains the omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), and also vitamin A and vitamin D. Histori ...

, an important source of

vitamin A Vitamin A is a fat-soluble vitamin and an essential nutrient for humans. It is a group of organic compounds that includes retinol, retinal (also known as retinaldehyde), retinoic acid, and several provitamin A carotenoids (most notably ...

,

vitamin D Vitamin D is a group of fat-soluble secosteroids responsible for increasing intestinal absorption of calcium, magnesium, and phosphate, and many other biological effects. In humans, the most important compounds in this group are vitamin D3 (c ...

,

vitamin E Vitamin E is a group of eight fat soluble compounds that include four tocopherols and four tocotrienols. Vitamin E deficiency, which is rare and usually due to an underlying problem with digesting dietary fat rather than from a diet low in vi ...

and

omega-3 fatty acid Omega−3 fatty acids, also called Omega-3 oils, ω−3 fatty acids or ''n''−3 fatty acids, are polyunsaturated fatty acids (PUFAs) characterized by the presence of a double bond, three atoms away from the terminal methyl group in their chem ...

s (

EPA The Environmental Protection Agency (EPA) is an independent executive agency of the United States federal government tasked with environmental protection matters. President Richard Nixon proposed the establishment of EPA on July 9, 1970; it be ...

and

DHA DHA, Dha and dha may refer to: Chemicals * Docosahexaenoic acid, a 22:6 omega-3 fatty acid * Dehydroandrosterone, an endogenous androgenic steroid * Dehydroascorbic acid, an oxidized form of ascorbic acid * Dehydroacetic acid, a pyrone derivati ...

). Young Atlantic cod or

haddock The haddock (''Melanogrammus aeglefinus'') is a saltwater ray-finned fish from the family Gadidae, the true cods. It is the only species in the monotypic genus ''Melanogrammus''. It is found in the North Atlantic Ocean and associated seas wher ...

prepared in strips for cooking is called

scrod Scrod or schrod () is a small cod or haddock, and sometimes other whitefish (fisheries term), whitefish, used as food. It is usually served as a fish fillet, fillet, though formerly it was often split instead. In the wholesale fish business, scro ...

. In the

United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the European mainland, continental mainland. It comprises England, Scotlan ...

,

Atlantic cod The Atlantic cod (''Gadus morhua'') is a benthopelagic fish of the family Gadidae, widely consumed by humans. It is also commercially known as cod or codling.fish and chips, along with

haddock The haddock (''Melanogrammus aeglefinus'') is a saltwater ray-finned fish from the family Gadidae, the true cods. It is the only species in the monotypic genus ''Melanogrammus''. It is found in the North Atlantic Ocean and associated seas wher ...

and

plaice Plaice is a common name for a group of flatfish that comprises four species: the European, American, Alaskan and scale-eye plaice. Commercially, the most important plaice is the European. The principal commercial flatfish in Europe, it is al ...

. Cod's soft liver can be tinned (canned) and eaten.

History

Cod has been an important economic commodity in

international market Global marketing is defined as “marketing on a worldwide scale reconciling or taking global operational differences, similarities and opportunities in order to reach global objectives". Global marketing is also a field of study in general busin ...

s since the

Viking Vikings ; non, víkingr is the modern name given to seafaring people originally from Scandinavia (present-day Denmark, Norway and Sweden), who from the late 8th to the late 11th centuries raided, pirated, traded and se ...

period (around 800 AD).

Norwegians Norwegians ( no, nordmenn) are a North Germanic ethnic group and nation native to Norway, where they form the vast majority of the population. They share a common culture and speak the Norwegian language. Norwegians are descended from the N ...

travelled with dried cod and soon a dried cod market developed in southern

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a subcontinent of Eurasia and it is located entirel ...

. 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. The

Portuguese Portuguese may refer to: * anything of, from, or related to the country and nation of Portugal ** Portuguese cuisine, traditional foods ** Portuguese language, a Romance language *** Portuguese dialects, variants of the Portuguese language ** Portu ...

began fishing cod in the 15th century.

Clipfish Dried and salted cod, sometimes referred to as salt cod or saltfish or salt dolly, is cod which has been preserved by drying after salting. Cod which has been dried without the addition of salt is stockfish. Salt cod was long a major export o ...

is widely enjoyed in Portugal. The Basques played an important role in the cod trade, and allegedly found the Canadian fishing banks before

Columbus Columbus is a Latinized version of the Italian surname "''Colombo''". It most commonly refers to: * Christopher Columbus (1451-1506), the Italian explorer * Columbus, Ohio, capital of the U.S. state of Ohio Columbus may also refer to: Places ...

' discovery of America. 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 Massachusetts (Massachusett: ''Muhsachuweesut Massachusett_writing_systems.html" ;"title="nowiki/> məhswatʃəwiːsət.html" ;"title="Massachusett writing systems">məhswatʃəwiːsət">Massachusett writing systems">məhswatʃəwiːsət'' En ...

, 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 centers. The large cod fisheries along the coast of

North Norway Northern Norway ( nb, Nord-Norge, , nn, Nord-Noreg; se, Davvi-Norga) is a geographical region of Norway, consisting of the two northernmost counties Nordland and Troms og Finnmark, in total about 35% of the Norwegian mainland. Some of the larg ...

(and in particular close to the

Lofoten Lofoten () is an archipelago and a traditional district in the county of Nordland, Norway. Lofoten has distinctive scenery with dramatic mountains and peaks, open sea and sheltered bays, beaches and untouched lands. There are two towns, Svolv� ...

islands) have been developed almost uniquely for

export An export in international trade is a good produced in one country that is sold into another country or a service provided in one country for a national or resident of another country. The seller of such goods or the service provider is an ...

, depending on sea transport of stockfish over large distances. Since the introduction of salt,

dried and salted cod Dried and salted cod, sometimes referred to as salt cod or saltfish or salt dolly, is cod which has been preserved by drying after salting. Cod which has been dried without the addition of salt is stockfish. Salt cod was long a major export ...

(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 Bergen (), historically Bjørgvin, is a city and municipality in Vestland county on the west coast of Norway. , its population is roughly 285,900. Bergen is the second-largest city in Norway. The municipality covers and is on the peninsula o ...

as the most important port.

William Pitt the Elder William Pitt, 1st Earl of Chatham, (15 November 170811 May 1778) was a British statesman of the Whig group who served as Prime Minister of Great Britain from 1766 to 1768. Historians call him Chatham or William Pitt the Elder to distinguish ...

, criticizing the

Treaty of Paris Treaty of Paris may refer to one of many treaties signed in Paris, France: Treaties 1200s and 1300s * Treaty of Paris (1229), which ended the Albigensian Crusade * Treaty of Paris (1259), between Henry III of England and Louis IX of France * Trea ...

in

Parliament In modern politics, and history, a parliament is a legislative body of government. Generally, a modern parliament has three functions: representing the electorate, making laws, and overseeing the government via hearings and inquiries. Th ...

, 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 Massachusetts (Massachusett: ''Muhsachuweesut Massachusett_writing_systems.html" ;"title="nowiki/> məhswatʃəwiːsət.html" ;"title="Massachusett writing systems">məhswatʃəwiːsət">Massachusett writing systems">məhswatʃəwiːsət'' En ...

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 The Molasses Act of 1733 was an Act of the Parliament of Great Britain (citation 6 Geo II. c. 13) that imposed a tax of six pence per gallon on imports of molasses from non-British colonies. Parliament created the act largely at the insistence ...

, 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". 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 Iceland ( is, Ísland; ) is a Nordic island country in the North Atlantic Ocean and in the Arctic Ocean. Iceland is the most sparsely populated country in Europe. Iceland's capital and largest city is Reykjavík, which (along with its s ...

re-emerged as a fishing power and entered the

Cod Wars The Cod Wars ( is, Þorskastríðin; also known as , ; german: Kabeljaukriege) were a series of 20th-century confrontations between the United Kingdom (with aid from West Germany) and Iceland about fishing rights in the North Atlantic. Each of ...

. 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

In 1992 the Canadian Federal Minister of Fisheries and Oceans,

John Crosbie John Carnell Crosbie, (January 30, 1931 – January 10, 2020) was a Canadian provincial and federal politician who served as the 12th lieutenant governor of Newfoundland and Labrador, Canada. Prior to being lieutenant governor, he served as a p ...

, declared a moratorium on the Northern Cod fishery, which for the preceding 500 years had largely shaped the lives and communities of Canada's eastern coast. Fishing societies interplay with the resources which they depend on: fisheries transform the ecosystem, which pushes the fishery and society to adapt. In the summer of 1992, when the Northern Cod biomass fell to 1% of earlier levels, Canada's federal government saw that this relationship had been pushed to the breaking point, and declared a moratorium, ending the region's 500-year run with the Northern Cod. Observations on the reduced number and size of cod, and concerns of fishermen and marine biologists was offered, but generally ignored in favour of the uncertain science and harmful federal policies of Canada's Department of Fisheries and Oceans until the undeniable complete collapse of the fishery. According to any reasonable analysis, the collapse was first due to massive overfishing. Second, the dependence for maintenance of the fishery itself on the

nutrient cycle A nutrient cycle (or ecological recycling) is the movement and exchange of inorganic and organic matter back into the production of matter. Energy flow is a unidirectional and noncyclic pathway, whereas the movement of mineral nutrients is cyc ...

that was being disrupted by removal of megatons of biomass from a closed system resulted in the starvation of the residual fish.

References

External links

Codtrace

fishbase.org – Scientific Names for GadusFisheries Heritage website, Newfoundland and LabradorSpecies factsheet on cod from the UK Sea Fish Industry Authority (PDF, 2MB)
* {{Authority control Commercial fish Gadidae Fish common names

Species

Cod in the genus ''Gadus''

Related species

Other species

Perciformes

Rock cod, reef cod, and coral cod

Scorpaeniformes

Ophidiiformes

Marketed as cod

Characteristics

Life cycle

Ecology

Fisheries

Aquaculture

As food

History

Collapse of the Atlantic northwest cod fishery

See also

References

Further reading

External links