COD, the name given to the typical fish of the family Gadidae, of the Teleostean suborder Anacanthini, the position of which has much varied in our classifications. Having no spines to their fins, the Gadids used, in Cuvierian days, to be associated with the herrings, Salmonids, pike, etc., in the artificially-conceived order of Malacopterygians, or soft-finned bony fishes. But, on the ground of their air-bladder being closed, or deprived of a pneumatic duct communicating with the digestive canal, such as is characteristic of the Malacopterygians, they were removed from them and placed with the flat-fishes, or Pleuronectidae, in a suborder Anacanthini, regarded as intermediate in position between the Acanthopterygians, or spiny-finned fishes, and the Malacopterygians. It has, however, been shown that the flat-fishes bear no relationship to the Gadids, but are most nearly akin to the John Dories (see Dory).
The suborder Anacanthini is, nevertheless, maintained for the Muraenolepididae Gadids and two related families, Macruridae and Muraenolepididae, and may be thus defined: - Air-bladder without open duct. Parietal bones separated by the supra-occipital; prootic and exoccipital separated by the enlarged opisthotic. Pectoral arch suspended from the skull: no mesocoracoid arch. Ventral fins below or in front of the pectorals, the pelvic bones posterior to the clavicular symphysis and only loosely attached to it by ligament. Fins without spines; caudal fin, if present, without expanded hypural, perfectly symmetrical, and supported by the neural and haemal spines of the posterior vertebrae, and by basal bones similar to those supporting the dorsal and anal rays. This type of caudal fin must be regarded as secondary, the Gadidae being, no doubt, derived from fishes in which the homocercal fin of the typical Teleostean had been lost.
About 120 species of Gadids are distinguished, mostly marine, many being adapted to life at great depths; all are carnivorous. They inhabit chiefly the northern seas, but many abyssal forms occur between the tropics and in the southern parts of the Atlantic and Pacific. They are represented in British waters by eight genera, and about twenty species, only one of which, the burbot (Lota vulgaris), is an inhabitant of fresh waters. Several of the marine species are of first-rate economic importance. The genus Gadus is characterized by having three dorsal and two anal fins, and a truncated or notched caudal fin. In the cod and haddock the base of the first anal fin is not, or but slightly, longer than that of the second dorsal fin; in the whiting, pout, coal-fish, pollack, hake, ling and burbot, the former is considerably longer than the latter.
The cod, Gadus morrhua, possesses, in common with the other members of the genus, three dorsal and two anal fins, and a single barbel, at least half as long as the eye, at the chin. It is a widely-distributed species, being found throughout the northern and temperate seas of Europe, Asia and America, extending as far south as Gibraltar, but not entering the Mediterranean, and inhabits water from 25 to 50 fathoms deep, where it always feeds close to the bottom. It is exceedingly voracious, feeding on the smaller denizens of the ocean - fish, crustaceans, worms and molluscs, and greedily taking almost any bait the fisherman chooses to employ. The cod spawns in February, and is exceedingly prolific, the roe of a single female having been known to contain upwards of eight millions of ova, and to form more than half the weight of the entire fish. Only a small proportion of these get fertilized, and still fewer ever emerge from the egg. The number of cod is still further reduced by the trade carried on in roe, large quantities of which are used in France as ground-bait in the sardine fishery, while it also forms an article of human food. The young are about an inch in length by the end of spring, but are not fit for the market till the second year, and it has been stated that they do not reach maturity, as shown by the power of reproduction, till the end of their third year. They usually measure about 3 ft. in length, and weigh from 12 to 20 lb, but specimens have been taken from 50 to 70 lb in weight.
As an article of food the cod-fish is in greatest perfection during the three months preceding Christmas. It is caught on all parts of the British and Irish coasts, but the Dogger Bank, and Rockall, off the Outer Hebrides, have been specially noted for their cod-fisheries. The fishery is also carried on along the coast of Norfolk and Suffolk, where great quantities of the fish are caught with hook and line, and conveyed to market alive in "well-boats" specially built for this traffic. Such boats have been in use since the beginning of the 18th century. The most important cod-fishery in the world is that which has been prosecuted for centuries on the Newfoundland banks, where it is not uncommon for a single fisherman to take over 500 of these fish in ten or eleven hours. These, salted and dried, are exported to all parts of the world, and form, when taken in connexion with the enormous quantity of fresh cod consumed, a valuable addition to the food resources of the human race.
The air-bladder of this fish furnishes isinglass, little, if at all, inferior to that obtained from the sturgeon, while from the liver is obtained cod-liver oil, largely used in medicine as a remedy in scrofulous complaints and pulmonary consumption (see Cod-liver Oil ). "The Norwegians," says Cuvier, "give cod-heads with marine plants to their cows for the purpose of producing a greater proportion of milk. The vertebrae, the ribs, and the bones in general, are given to their cattle by the Icelanders, and by the Kamtchatdales to their dogs. These same parts, properly dried, are also employed as fuel in the desolate steppes of the Icy Sea."
At Port Logan in Wigtonshire cod-fish are kept in a large reservoir, scooped out of the solid rock by the action of the sea, egress from which is prevented by a barrier of stones, which does not prevent the free access of the water. These cod are fed chiefly on mussels, and when the keeper approaches to feed them they may be seen rising to the surface in hundreds and eagerly seeking the edge. They have become comparatively tame and familiar. Frank Buckland, who visited the place, states that after a little while they allowed him to take hold of them, scratch them on the back, and play with them in various ways. Their flavour is considered superior to that of the cod taken in the open sea.
(G. A. B.)
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)