FISHES OF THE GULF OF MAINE 417 



whence they are driven by extremes of heat and cold at another) ; and third, the 

 breeding migrations, in the course of which the mature fish congregate in certain 

 localities to spawn. 



The eggs, larvse, and young fry of the cod, like those of so many other sea 

 fishes, drift helplessly with the current from the time they are spawned imtil they 

 seek the bottom (a fact established by European observations too numerous to 

 list), and in European seas young cod often live under the disks of the large red 

 jellyfish (Cyanea), though they have not yet been found in this situation in the 

 Gulf of Maine. This period varies in different in different seas, depending to 

 some extent on whether the fry are near land or far out at sea, floating over deep 

 water or shoal; and while no definite information has been obtained on this point 

 for the Gulf of Maine, it is probable that most of the fish hatched on the inshore 

 spawning groimds sink when not over two months old or an inch long, for they 

 are in water so shoal that the bottom is within easy reach. During this involun- 

 tary migration the young cod tend to follow the general coast line of the Gulf 

 from northeast to southwest, either to swing offshore toward the southeast part 

 of the Gulf and so to Georges Bank, or to circle around toward the coast of Nova 

 Scotia and the Bay of Fimdy. Our few captures of pelagic cod fry have all been 

 in the southwestern part of the Gulf, in which they agree with haddock, silver 

 hake, and most of the common flatfishes; while it is probable that the fry taken 

 in tow nets at Woods Hole in March, April, and May have worked inshore thitlier 

 from the spawning grounds on Nantucket Shoals. Furthermore, the general 

 eddylike circulation of the GuK suggests that some of the larvae hatched on Georges 

 Bank may reach the Bay of Fundj^ region and the eastern Maine coast before 

 they take to bottom. Others of them, however, may seek the deeper bottom of 

 the offshore grounds, near v\'hich they were perhaps produced. 



Little is known of the life or wanderings of the cod in the Gulf of Maine from 

 this stage until it is large enough to be caught on hook and line — say 2 or 3 

 years old. Such of them as come into very shoal water at first gradually work 

 out again into deeper as they grow, their later journeyings largely taking the form 

 of feeding migrations in search of food; and although it seems that small cod do 

 not travel as much as large ones do, they v/ander sufficiently to populate the entire 

 coast line of the open Gulf including the outer part of the Bay of Fundy, where 

 there are cod of all sizes from yearlings on though none are hatched there (p. 426). 

 Similarly, the investigations of 1913 proved that there are about as many little cod 

 (less than 1 pound in weight) as large on Georges Bank and in the South Channel. 



Some bodies of cod wander more than others, and two groups are generally . 

 recognized by Gulf of Maine fishermen — the "shore'' or "ground" fish and the 

 "school" fish. The former apparently remain throughout the year on rocky 

 patches near land, feeding on the bottom, and they probably travel very little out 

 of spawning time except as they gradually exhaust the food supply in one spot and 

 are therefore driven to move on to fresh pastures. Such fish are usually dark and 

 dull colored, with large heads, and feed chiefly on bottom. The red fish that haunt 

 the rocks belong to this category, and while as a rule these are immature fish that 

 lose their red color as they grow larger, a red ' " rock " fish as large as 10 or 20 pounds 

 is sometimes caught. 



