Cod (Gadus), a genus of bony fishes in the soft-rayed order (Anacanthini), and type of a family (Gadidae) which includes some valuable food-fishes, such as Ling (Molva), Hake or 'Stockfish' (Merluccius), Burbot (Lota), &c. The genus Gadus itself is undoubtedly the most valuable. A moderately elongated body with small smooth scales, the three dorsal and two anal fins, the distinctness of the tail from the fins, the position of the pelvic limbs on the throat, the toothed vomer and toothless palatine, are among the more important distinctive features. The genus includes about a score of species, distributed in the cold and temperate seas of the northern part of the globe, and well known to be very abundant off Newfoundland, at the Lofoten Islands, and on the Dogger Bank. They seem to follow the herring shoals. As part of our food-supply, and as sources of cod-liver oil, the species of Gadus are of great economic importance.
Besides the cod proper (G. morhua), the following species are well known: the Haddock (q.v., G. aeglefinus), the Whiting (q.v., G. merlangus), the Bib or Whiting-pout (G. luscus), the Power-cod (G. minutus), the Pollack (G. pollachius), the Coal-fish (G. virens).
The cod itself is too familiar an animal to demand description. It attains a length of 2 to 4 feet, and may weigh as much as 100 lb. The sensitive barbule on the chin is tolerably long. The colour varies considerably. A smaller variety (dorse) is sometimes distinguished—e.g. in the Baltic. The cod occurs between 50° and 75° N. lat. in great profusion, to a depth of 120 fathoms, but is not found nearer the equator than 40° lat. It spawns from January to May, according to the climate, and it is only at this season that numbers crowd together. The cod is very voracious, and feeds at the bottom on crustaceans, molluscs, worms, and even on small fishes. They are very prolific, and it has been calculated that the roe of a large female may contain towards 9 million eggs. The productiveness of the great banks of Newfoundland excels that of all others, but the cod-fisheries near the coasts of Sweden, Iceland, and the north of Scotland are also important. The Dutch were engaged in the cod-fishery as early as the middle of the 14th century, and the English resorted for this purpose to the coasts of Iceland about the same period. The French have also engaged largely in the cod-fishery. The fishery is always carried on by means of lines and hooks, partly by long-lines and partly by hand-lines. Whelks and the like are used for bait. One man has been known to catch from 400 to 550 fish, on the banks of Newfoundland, in ten or eleven hours; and eight men to take eighty score in a day on the Dogger Bank. Great quantities of dried cod are carried from Newfoundland to the West Indies, and are consumed also in the Roman Catholic countries of the south of Europe. The principal seat of the cod-liver oil industry, in which other species are also utilised, is on the Norwegian coast. The preserved 'sound' or swim-bladder of the cod is esteemed a delicacy. It is also used in a dried state as isinglass. See Day's British Fishes, and Günther's Introduction to the Study of Fishes.