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SYSTEMATIC ZOOLOGY 



mostly tropical, fresh-water fishes, though some are marine, 

 varying in size from five centimeters to two meters, and are 

 most abundant in South America; they are also numerous in 

 the rivers of Africa. The common horned pout or bullhead of 

 our Northern and Eastern states is not large, but a good food 

 fish, and has been introduced into California; no catfishes are 

 native west of the Rock}- Mountains. The stone cats, about 

 fifteen centimeters in length, are found in our South and West. 

 The largest North American catfishes are the Great Lake cat- 



FlG. 236. Amiurus cuius, a catfish ; reduced. (From Shipley and Ma 



fish, often exceeding fifty kilos in weight, and the Mississippi 

 cat, which may weigh almost twice as much. The electric cat- 

 fish of the Nile, Malapterurus electricus, can give a considerable 

 electric shock like Torpedo, the electric ray. But the most 

 powerful shock given by any fish is that of the electric eel of 

 Brazil, Gymnotus electricus. It is eel-like in shape and attains 

 a length of about two meters ; the skin is entirely naked, with- 

 out scales. 



The carp family, Cyprinidae, is a very large family of fresh- 

 water fishes, distributed over the whole world except South 

 America, Australia, and the Polar regions. They are of little 

 value as food, but many are favorites in the ponds of private 

 and public parks, particularly the goldfishes, natives of China, 

 which retain their gold color only under domestication. If 

 allowed to live wild in open streams, they revert to their natural 

 olive color. The sardines, little marine fishes related to the 

 herrings and the anchovies, are preserved in oil in southern 

 Europe in great numbers; this is considered the best sardine, 

 but the California sardine, a related species, is also of consider- 



