THE FISHES 



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after they are fertilized, to leave them to their fate. Many 

 marine fishes like the flounders lay eggs that float on the 

 surface and are protected from their enemies by their 

 remarkable transparency. Some species make nests for 

 receiving the eggs; it is usually the male which performs 

 this task. 



In the common dogfish, or Amia, of our lakes and 

 streams the male constructs a rude nest by pushing about 

 some stones on the bottom and then induces a female to 

 enter the nest where she deposits her eggs or, in the lan- 



FIG. 129. Showing the nest of a horned dace with the male and 

 female fish on the nest. The stream flows in the direction indicated by 

 the arrows. (After Reighard.) 



guage of fishermen, " spawns. " The male after fertilizing 

 the eggs stands guard over them and rushes out to attack 

 any other fish that ventures too near the sacred premises. 

 Even after the eggs hatch, the male accompanies the young 

 brood until they begin to scatter and shift for themselves. 

 The male of the common stickleback constructs a more 

 elaborate nest out of sticks and bits of grass and weeds. 

 The males are irascible little creatures and defend the 

 nest with much valor. In certain marine catfishes the 

 male protects the eggs by carrying them in his mouth. 



Those fishes which simply lay their eggs in the water with- 

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