The Cod Family and Its Utilization JOHN J. RYAN Figure I.-Atlantic cod. Introduction without dried cod, for ships could carry cod, Gadus macrocephalus; 6) Atlantic no perishable food as staples. cod, Gadus morhua morhua; 7) Green­ Spanish explorers came to the New The cod family, from an economic land cod, Gadus ogac; 8) cusk, Brosme World to find gold and precious stones, point of view, is the most important of brosme; 9) fourbeard rockling, En­ but the French and Portuguese, fol­ all the families of fishes. The members chelyopus cimbrius; 10) burbot, Lota lowed by the English, crossed the At­ of the cod family are second only to the Iota; 11) haddock, Melanogrammus lantic to catch fish, especially the Atlan­ herring family in volume of commer­ aeglefinus; 12) silver hake (whiting), tic cod, Gadus morhua. In the 16th cial landings (Table 1). In contrast to Merluccius bilinearis; 13) Pacific hake, century, French and Portuguese vessels the herring family, which is often used Merluccius productus; 14) longfin fished the Grand Bank off Newfound­ for industrial purposes, almost all hake, Phycis chesteri; 15) luminous land. By the early 17th century, the of the cod, haddock, hakes, and whit­ hake, Steindachneria argentea; 16) red New England colonists were fishing for ings are used for human food. In hake, Urophycis chuss; 17) Gulf hake, cod (Fig. 1) in the local waters. In 1624 1976, 12,116,000 metric tons (t) Urophycis cirratus; 18) Carolina hake, "not less than 50 vessels from Glouces­ (26,710,000,000 pounds) of the cod Urophycis earlli; 19) southern hake, ter" fished with handlines off the coast. family were landed worldwide as Urophycis fioridanus; 20) spotted In 1748, the first catch of cod from compared with 15,089,000 t hake, Urophycis regius; 21) white Georges Bank was landed. (33,196,000,000 pounds) of the her­ hake, Urophycis tenuis; 22) Pacific Cod probably has influenced the ring family (Food and Agriculture Or­ tomcod, Microgadus proximus; 23) At­ course of American history more than ganization,1976). lantic tomcod, Microgadus tomcod; any other marine fish. It's white flaky 24) Atlantic pollock, Pollachius vir­ Classification flesh was the foundation of power and ens; and 25) walleye (Alaska) pollock, wealth in colonial America. Cod was to Twenty-five species of fishes in the Theragra chalcogramma. young America what coffee was in re­ cod family, Gadidae, are listed by the Although European ichthyologists cent years to Brazil; it was the first American Fisheries Society (Bailey et separate the hakes and the cods because product shipped out of colonial Mas­ aI., 1970). They include the following: of differences in the structure of the sachusetts. A large wooden codfish 1) Toothed cod, Arctogadus borisovi; skull and ribs, some American experts carving was hung in the Massachusetts 2) polar cod, Arctogadus glacialis; 3) group them into a single family, and State House in 1784 and is still occupy­ Arctic cod, Boreogadus saida; 4) saf­ they are so listed by the American ing an honored position there. fron cod, Eleginus gracilis; 5) Pacific Fisheries Society. As a commercial fish, cod had no peer: It was abundant all year. When split, salted, and dried, it kept almost indefinitely in any climate. Many long Table 1.-World commercial catch of fish by species groups, 1973-76. voyages could not have been possible Catch (1,000 t) Species group 1973 1974 1975 1976 Herring, sardines, anchovies, el al. 11,314 13,888 13,618 15,089 Cods, hakes, haddock, et al. 11,970 12,699 11,882 12,116 Freshwater fishes 9,293 9,244 9,599 9,532 John 1. Ryan is a Supervisory Research Food Miscellaneous marine and Technologist at the Gloucester Laboratory, diadromous fishes 8,676 8,382 8,021 8,445 Northeast Fisheries Center,. ational Marine Jacks, mullets, sauries, et al. 5,740 5,454 5,935 7,389 Fisheries Service, NOAA, Emerson Avenue, Radlish, basses, congers, et al. 4,320 4,865 5,071 4,950 Gloucester, MA 01930. Source: "Yearbook of Fishery Statistics, 1976," FAD, Rome, Vol. 42. November 1979 25 , , i--------- SPINES --- -------:-- -_.- RAYS- --1 clams, crabs, and squid. When hungry, I I I I it will eat almost anything such as false I I I I teeth, old boots, and pieces of wood. At I I I I times, it eats small floating mollusks I I I I I I which cause its flesh to exhibit a strong I I I I odor of iodine when cooked. I I I I I Cod migrate principally because of I I changes in the temperature of the water, I I I better availability of food, and the I I search for suitable spawning locations. I I Growth rates differ from ground to .,."'.. I 0~ I .X I ground, but the cod is a relatively fast growing fish and can theoretically live to an age of 50 years. A I-year-old cod Figure 2.-Rays and spines. is usually about 7 inches (17.8 em) long; a 2-year-old will be about 14 inches (35.6 cm); and by the end of the third year, the cod is about 22 inches The Cods Alaska. Additionally, the Pacific cod, (55.9 cm) long. Growth is slower in Gadus macrocephalus, is considered colder waters. Cod in Arctic waters The cads, family Gadidae, are soft­ by most taxonomists as a separate reach maturity in 6-8 years at 6-8 inches finned fish lacking true spines; but in species. (15.2-20.1 em) in length. the whiting, the dorsal and anal fin rays The cod is one of the more prolific are so stiff as to feel like spines. The fishes. It has been calculated that if all Atlantic Cod cod family is distinguished from other the eggs spawned by all female cod in soft-rayed fishes (Fig. 2) by the fact that The Atlantic cod lFig. 1) is oval in one spawning season were to survive, the large pelvic fins are situated under cross-section with three distinct dorsal the oceans would be one mass of cod or in front of the pectorals and not be­ fins, two anal fins, and a nearly square (Jensen, 1972). One female cod may hind them as in salmon and herring. tail. Its color varies from olive green to release from 3 to 7 million eggs at a The cads are generally fishes of cold reddish brown depending on the time. A 75-pound (34.0-kg) female cod water, and most of them live close to background of its habitat. The lateral can produce 9.1 million eggs. Spawn­ the bottom. line is white, and the skin has many ing takes place in shallow (5-25 Codfish are found on both sides of small scales. Most cod average about 3 fathoms or 9.15-45.7 m) waters usually the Atlantic Ocean, in the north Pacific feet (0.9 m) in length and weigh from in the early spring. The eggs are Ocean, and in the Arctic Ocean down to 10 to 25 pounds (4.5 to 11.3 kg). buoyant and transparent without oil about 250 fathoms (457 m). The best A giant cod was caught by commer­ globule and 1/20-1/16 inch (1.27-1.59 cod fishing grounds are offshore banks cial fishermen off the northern Mas­ mm) in diameter. At 43°F (6.2°C), including Georges Bank 150 miles (240 sachusetts coast on a Iine trawl in May hatching may be expected in 14 or 15 km) off Boston, Mass., and Grand 1895 (Jordan and Evermann, 1902). It days. The newly hatched larvae feed Bank off Newfoundland where modern measured over 6 feet (1.83 m) in length mainly on plankton and drift with sur­ trawlers may take 35 tons of cod in only and weighed 21114 pounds (95.8 kg). face currents. When the larvae have a few hours of fishing. This was an old fish, but no one knows grown to a length of about 3 inches (7.6 The most important of the cads is the how old. cm), they move to the ocean bottom Atlantic cod, which includes several The cod is found on both sides of the where they feed on worms and small geographical subspecies. These are the North Atlantic Ocean and Arctic Ocean shrimps. Only a few eggs out of the Baltic cod, Gadus morhua callarias, down to about 1,500 feet (457.2 m). millions spawned will survive and be­ found in the Baltic Sea and parts of the Although the cod is a demersal or bot­ come mature fish. North Sea; theKildin Island cod, Gadus tom-living fish, when in search of food Pacific Cod morhua kildinensis, which lives in a salt it may be found near the surface. It pond, Lake Mogilno, on an island in the prefers rocky, pebbly, or sandy bot­ The Pacific cod, Gadus macrocepha­ Baltic Sea; and the White Sea cod, toms, and water temperatures from 32° lus. (Fig. 3) is also known as cod, true Gadus morhua marisalbi, found in the to 500f (0° to lO°C). cod, and gray cod. In appearance and Arctic Sea. The Greenland cod, Gadus The adult cod feeds mostly on small­ habits, it resembles its cousin, the At­ ogac, often considered a separate er fish such as sand eels, Ammodytes lantic cod. In 1976, close to species, is found mostly in inlets and in sp.; capelins, Mallotus sp.; herrings, 11.900,000 pounds (5,400 t) of Pacific the shallow water of the Arctic Ocean Clupeidae; and other small cod, and/or cod were landed in the United States from West Greenland to Point Barrow, shellfish such as shrimp, mussels, with a value of$1.5 million (Robinson, 26 Marine Fisheries Review 1977).