WHITEFISHES, a name given in the )'sited States to various species of salmonoid fishes of the genus Coregonas and sometimes to those of Argyrosonsus, more properly desig nated ciscoes. Coregonwt has a comparatively small and nearly toothless mouth, the pre maxillary bones broad and with the vertical, and the lower jaw short. e thin cycloid scales are much larger than in the salmons and trouts, and the caudal fin is deeply forked. Internally, the stomach is horse-shoe shaped and provided with very numerous pylonc caeca, and the swim-bladder is very large. The species, about 15 in num ber, though some ichthyologists recognize many more, are confined to the clear lakes of the northern portions of the northern hemisphere often extending into the Arctic regions and sometimes there becoming anadromous. Wher ever found they are highly valued for food. North America has about eight species. The common whitefish (C. ehoptifortntos) has its centre of distribution in the Great Lakes, but extends into the various lake systems of New York and southern Canada. It reaches a length of two feet and may be distinguished from the related species by its numerous and long gill rakers, the toothless mouth and the elevoted but not compressed back. As generally in the whitefishes, the color is olivaceous above and white below. It receives various local names from the fishermen, such as buffalo-back; and the variety landlocIced in Otsego Lake at the head of the Susquehanna River is known as the Otsego bass. During the greater part of the year the whitefish remains in the deeper waters of the lakes, moving about in schools which change their feeding grounds with considerable regularity. Being toothless they feed only upon small animals, such as crustaceans, snails and insect larvae, the first being by far the most important part of their diet. During the late fall and early winter the schools congregate on the shallows to spawn; in the act of spawn ing the female rises to the surface and is•nme diately followed by a male which mingles the sperm with the stream of eggs issuing from her vent. The eggs are about one-eighth of an inch in diameter and sink to the bottom, where most of them are eaten by the small fishes and mud puppies which swarm on the spawning grounds. They develop slowly and require several weeks to hatch, the exact time depending upon the temperature of the water. Each female pro duces from 10,000 to 75,000 eggs, depending upon her size.
Besides the enemies affecting the eggs and young the adult whitefish are preyed upon by the large pike and lake-trout which follow the schools, and to a less extent by smaller preda ceous fishes. The extensive development of the fisheries, which are prosecuted most vigorously at the very season when the spawning fish are most accessible on the shallows, has so depleted the numbers of the whitefish that the fisheries are now dependent upon artificial propagation for their maintenance. The methods are essen tially the same as those employed in the artifi cial propagation of the she though many modifications in detail have been found neces sary. Hundreds of millions ofare now
annually taken and hatched under auspices of the United States and State commissions of fisheries. Such extensive and even greater operations are required to sustain these fish eries at a point of production equal to sans lying the demand of the market. These figures represent the American catch alone and dur ing the same year the Canadian fisheries prob ably yielded about 40,000,000 pounds more. Whitefish are sold fresh or are frozen imme diately after capture and placed in cold storage at a temperature several degrees below freez ing and in this condition shipped, especially during the winter, to all parts of the country. Relatively small quantities are also pickled or smoked.
Other species of Coreponus are found in the Great Lakes as well as in other lakes particu larly northward and westward, but at the pres ent time none are so highly valued as the com mon whitefish. An important one is the shad waiter or round whitefish (G. quadrilaterals). The genus Argyrosornus, however, includes two species of great and increasing importance, though inferior in quality to the common white fish. The genus differs from Coregonus chiefly in the projecting lower jaw, larger mouth and horizontal premaxillary bones. The numerous species are similarly distributed in North Amer ica, which has eight, and Asia, and ex cept for their great activity and predatory mode of life their habits in general resemble those of the true whitefishes. The cisco whit ing or lake herring (.4. artedi) is about a foot long, bluish or greenish above, with dark, speckled silvery sides. It abounds in shallow waters of the Great Lakes and, as indicated above, is of great commercial value. The moon-eye cisco (A. hoyi) has a very large eye and the sides are brilliantly silvery. It is about a foot long and is the object of a considerable fishery in the western part of Lake Michigan. It spawns in November in relatively deep water. A third important species of this genus is the blue-fin whitefish (A. rugripennis). from aU of the preceding which have pale fins by the blue-black color of its pectorals, anals and ventral. It attains a length of 18 inches and is plentiful in the deep waters of Lake Michigan and the small lakes of Minne sota and Wisconsin and thence northwestward to Athabasca.
Whitefishes seldom take the hook, but are captured by means of pound, trap and gill nets and to a smaller extent with seines. The pound and trap nets arc arranged in lines which sometimes reach to a distance of 10 or 12 miles from shore, while the gill nets are set much farther out in deep water and are weighted to the bottom.
Consult Brown Goode, 'Natural History of Aquatic Animals' (Washington 1884), and 'American Game and Food Fishes' (New York 1902); Townsend, 'Statistics of the Fish eries of the Great Lakes.' Report United States Fish Commission for 1901; and special papers of the Muted States Bureau of Fishes, and of the Canadian Fisheries Department.