Fish and Their Fabulous Neighbors [171 



and attains a weight of four hundred pounds. Among the giants 

 of the sea is that popular American food staple, the tuna. These 

 giants vary in size depending on the regions to which they are 

 native, but a weight of a thousand pounds is about the maximum. 

 Another big fish is the spectacular swordfish. Few sports are as 

 adventurous as deep-sea fishing, and many a boy or girl, thrilled 

 by pictures or films, looks forward to taking a marlin or sailfish 

 with rod and reel. 



Fish Migrate Too 



"What happened to the fish when the water froze?*' children 

 often ask as they prepare to go skating over ice that was a rippling 

 lake or stream only a few weeks before. 



There is more than one answer to this question. Some fish the 

 common sucker, for example burrow in the mud and may be 

 frozen and thawed without being any the worse! Others remain 

 active if the water under the ice is deep enough. As for carp and 

 some other species, they move en masse to deeper water at the 

 beginning of winter. 



Children accept the seasonal travels of birds rather casually 

 because they can witness some phases of their migrations each 

 year; but they are likely to be surprised to find that many fish 

 migrate too. Even their parents often do not realize how wide- 

 spread the migration habit is among fish. Except for the fish living 

 in ponds, a great many may make migratory journeys in the course 

 of their lives. Sometimes the individuals in a traveling "school" 

 are counted by the million. 



SPAWNING MIGRATIONS 



Aside from the journeys of fish to deeper waters for the 

 winter, some species of fresh-water fish travel many miles in 

 search of food. There are also salt-water migrations by fish that 

 swim away from their feeding grounds to deposit their eggs. A 

 famous example is that of the North Sea herring migrating in 

 the autumn to coastal waters off France. There they spawn and 

 go northward again. When the young hatch they swim to the 

 surface to feed and are gradually swept north by the main currents 



