The Structure of Game Fishes n 



jority separate. Many young of pelagic fishes 

 attach themselves to large jellyfishes; others to 

 the physalia, and some adults enter the intestinal 

 tube of holothurians. 



There are two other methods of reproduction 

 among fishes and the fishlike animals. In some, 

 as the surf-fishes and certain sharks, the young 

 are born alive. The young of twenty or thirty 

 or more surf-fishes school and swim together. 

 Other fishes are ovoviviparous, the eggs being 

 retained in the body until the young are hatched. 



In the vast concourse of fishes of the world 

 every possible habit is seen. Originally all were 

 doubtless salt-water forms, but they have entered 

 rivers and streams, and in time have become 

 adapted to their environment. Some fishes, 

 like the salmon, enter fresh water to spawn. 

 Others, like the eel, seem to reverse this. Cer- 

 tain fishes hibernate when water disappears. 

 Others cross overland to reach water, while 

 the strange periophthalmus and another genus 

 leave the water and wander along the shore in 

 search of food. 



The fishes are found at various depths of 

 the ocean, some at a depth of several miles 

 being blind. Those living in these abysmal 



