SOME COMMON FISHES OF NORTH AMERICA 283 



thing. Carp are accused of destroying the eggs of other fishes, 

 of driving other fishes away by stirring up mud, and of eating 

 aquatic vegetation and thus depriving wild ducks of their food. 



Catfishes (Fig. 164) are scaleless fish that, like the sturgeon, 

 live on the bottom and find their food by means of sensitive fila- 

 ments (barbels). The bullhead is a small catfish known to every 

 fisherman. The Mississippi catfish sometimes reaches a length 

 of five feet and a weight of over one hundred pounds. It is a 

 valuable food fish. 



A discussion of many of our food and game fishes will be found 

 in the next chapter. 



A few fish are worthy of space here because of their peculiar- 

 ities. Some of the cave fishes (Fig. 165, B) found in the river 

 Styx of the Mammoth Cave and in other 

 subterranean streams are blind. 



Certain species of fish living in warm seas 

 have greatly enlarged pectoral fins (Fig. 165, 

 A) which enable them to rise out of the 

 water and " fly " for as much as an eighth 

 of a mile. 



The true eels (Fig. 165, D) have very long, 

 cylindrical bodies shaped like that of the 

 lamprey eel, with which they should not be 

 confused. 



The sea horse (Fig. 166) is a fish only a 

 few inches long, with a head that reminds 

 one of the head of a horse. It can cling to 

 objects with its prehensile tail. The male 

 protects the eggs in a brood pouch. 



The remora (Fig. 165, C) is a fish that 

 clings to the body of a shark with its dorsal 

 fin which is modified as a sucker; it thus secures transportation 

 and possibly food when the shark has a meal. 



In the deep sea are many fishes with phosphorescent organs 

 distributed over the body; these may serve to illumine the sur- 



FIG. 1 66. The sea 

 horse, a, anus ; b.a, 

 branchial aperture; 

 m.p, brood pouch. 

 (From the Cambridge 

 Natural History.) 



