=Abundance of Food-fishes.=--In general, the economical value of any species depends not on its toothsomeness, but on its abundance and the ease with which it may be caught and preserved. It is said that more individuals of the herring (_Clupea harengus_ in the Atlantic, _Clupea pallasi_ in the Pacific) exist than of any other species. The herring is a good food-fish and whenever it runs it is freely sought. According to Björnsön, wherever the school of herring touches the coast of Norway, there a village springs up, and this is true in Scotland, Newfoundland, and from Killisnoo in Alaska to Otaru in Japan, and to Strielok in Siberia. Goode estimates the herring product of the North Atlantic at 1,500,000,000 pounds annually. In 1881 Professor Huxley used these words: [Illustration: FIG. 215.--Great Parrot-fish, or Guacamaia, _Pseudoscarus guacamaia_ Bloch & Schneider. Florida.] [Illustration: FIG. 216.--Striped Mullet, _Mugil cephalus_ (L.). Woods Hole, Mass.] "It is said that 2,500,000,000 or thereabout of herrings are every year taken out of the North Sea and the Atlantic. Suppose we assume the number to be 3,000,000,000 so as to be quite safe. It is a large number undoubtedly, but what does it come to? Not more than that of the herrings which may be contained in one shoal, if it covers half a dozen square miles, and shoals of much larger size are on record. It is safe to say that scattered through the North Sea and the Atlantic, at one and the same time, there must be scores of shoals, any one of which would go a long way toward supplying the whole of man's consumption of herrings." [Illustration: FIG. 217.--Mutton-snapper, or Pargo criollo, _Lutianus analis_ (Cuv. & Val.). Key West.] [Illustration: FIG. 218.--Herring, _Clupea harengus_ L. New York.] [Illustration: FIG. 219.--Codfish, _Gadus callarias_ L. Eastport, Maine.] The codfish (_Gadus callarias_ in the Atlantic; _Gadus macrocephalus_ in the Pacific) likewise swarms in all the northern seas, takes the hook readily, and is better food when salted and dried than it is when fresh. Next in economic importance probably stands the mackerel of the Atlantic (_Scomber scombrus_), a rich, oily fish which bears salting better than most. [Illustration: FIG. 220.--Mackerel, _Scomber scombrus_ L. New York.] Not less important is the great king-salmon, or quinnat (_Oncorhyanchus tschawytscha_), and the still more valuable blue-back salmon, or redfish (_Oncorhynchus nerka_). [Illustration: FIG. 221.--Halibut, _Hippoglossus hippoglossus_ (Linnæus). St. Paul Island, Bering Sea. (Photograph by U. S. Fur Seal Commission.)] The salmon of the Atlantic (_Salmo salar_), the various species of sturgeon (_Acipenser_), the sardines (_Sardinella_), the halibut (_Hippoglossus_), are also food-fishes of great importance.