COCYTUS (from Gr. kauein, to lament), a river of ancient Epirus which falls into the Acheron. Also, among the ancient Greeks, one of the rivers of the lower world.
COD, the typical representative (Gadus cal larias or Gachts morrlsa) of a family (Gadi rite, q.v.) of marine fishes of pre-eminent eco nomic importance. Although most widely and generally lcnown as the codfish, or simply cod, perhaps not less than 50 other names are applied to it more or less colloquially, many of them derived from the same root as cod. The cod is moderately elongated, heavy in front, with a large head, and tapering gradually into a slen der tail terminated by a slightly notched fin. There are three dorsal fins, none of which is elevated, and two anals, and the ventral fins are normal in structure and placed far forward on the throat. The mouth and eyes are large, and the chin bears a long barbel. Very small scales cover the entire body and most of the head. Although varying much in shade, the color is usually reddish-brown with small rounded spots of darker brown and a conspicuous pale lateral line. Unlike the haddocic, all the bones of the shoulder girdle are thin and lamellar. There is much variation in size, certain localities and schools always yielding large fish, others small or mixed. An average length is from three to four feet; and the weight from 7 to 40 pounds, but very much larger ones, several exceeding 100 pounds, and one of 160 pounds, have been recorded.
Thd cod is a cold water fish, preferring a temperature of from 35° to 45°. Whether there is more than a single species is doubtful, though it is well lcnown to fishermen and ichthyologists that the Alaskan cod have much larger swimming-bladders than those of the Atlantic. The cod may be said to have a circumpolar distribution, ranging south in the Atlantic as far as the Bay of Biscay on the European side, and to Cape Hatteras on the American shore. In the Pacific it is abundant in the waters of Alaska and Bering Sea, and occurs on banks off the mouth of the Columbia River. The cod is sometimes found as far north as 80 degrees and probably beyond. .Sometimes it enters fresh water, ascending rivers, as it formerly frequently did the Delaware, perhaps in pursuit of food. That any north-and-south migration takes place is doubtful, but seasonal migrations between deep and shallow waters, and irregular ones in search of food, are well known both on our coasts and on those of Europe. Thus Professor Sars has described the so-called °mountains of fish)) which annually approach the coast of Norway. North of Cape Cod the fish approach the shores during the summer, and retire, upon the approach of cold weather, to the deeper waters of the off-shore banks, where they are followed by the Glouces ter fishermen. On the shores of New Jersey
and Virginia no cod are found except during the winter, the shallow waters becoming so warmed in summer that they are driven sea ward to the cold Labrador current. Rocky and stony banks, where a rich fauna has con gregated at moderate depths to about 120 fathoms, are the favorite resorts of the cod, but considerable numbers are taken down to 250 fathoms on the edges of the outer banks, and the trawl has brought up cod from a depth of 300 fathoms.
The cod devours everything of an animal nature it comes across. Great clams are swallowed in their shells, and, after being digested, the hard parts are regurgitated in such numbers that the sea-bottom over large areas is said to be paved with them. Spawning talces place at moderate depths, but the buoyant eggs rise to the surface, where they float until hatched. On the European coasts the spawning season is in March and April, but with us dur ing the winter. The fecundity of the codfish is truly astounding, not less than 9,100,000 eggs having been estimated to be produced in a single year by a 75-pound fish, while Z000,000 to 4,000,000 is the average yield of those of ordi nary size. The eggs are small, about one-sev enteenth of an inch in diameter, and, although buoyant, have no oil globule, as do many other pelagic eggs. They hatch in from 12 days to 3 weeks, and the young fry, which feed on small crustaceans, grow rapidly, becoming about two inches long in four months and about one foot at the end of a year, though the variation in size is very great. That there has been a great decrease in the numbers of cod frequent ing the inshore banks is well known, and many suggestions have been made to account therefor. The late Professor Baird connected it with the decrease in the number and size of the schools of herrings, a favorite food of the cod, itself due to the building of dams and other obstruc tions which have prevented their entrance into the rivers for spawning purposes. In an at tempt to overcome this condition the United States Fish Commission has been engaged for several years in collecting and hatching enor mous numbers of cod eggs at its Gloucester and Woods Hole stations, with every promise of a considerable degree of ultimate success. Dur ing a recent winter, the last season for which statistics are available, no less than 338,000,000 cod eggs were thus handled.