466 



THE ANIMALS OF THE EARTH 



like pike, pickerel, and whitefish, live in fresh water and can be 

 caught in lakes and streams throughout the country. Others, 

 like haddock, live in salt water and can be caught only in the 

 open sea. Still other fish, such as salmon, shad, and smelt, spend 

 part of their time in salt water and part in fresh water, and 

 can be caught in either place. The habits of some fish make it 

 easy to catch them in large numbers; they usually swim in 



FIG. 336. A large fish net. 



groups, called schools, and a single haul of a net or a weir 

 may bring in hundreds and even thousands of fine specimens 

 (Fig. 336). 



In the United States, the most important fish are cod, shad, 

 herring, and salmon. All of these spend the greater part of their 

 life in the ocean, but leave the rough waters at the egg laying 

 season and swim up the rivers in search of a quiet place in 

 which to spawn or lay eggs. As soon as this journey upstream 

 begins, fishermen set their nets and weirs and haul in vast 



. 



" 



