CHAPTER XVII. 

 CARE OF FISH IN STORES. 



When fish are kept in tanks as merchandise by dealers, the loca- 

 tion of such receptacle should be well lighted, airy, and not per- 

 mitted to freeze. As was stated in another chapter, it is the oxygen 

 contained in the water that the fish breathes, and it is therefore nec- 

 essary to consider what means can be employed to keep up a contin- 

 uous supply of it. One way, the most in use, although the worst for 

 the retail customers, is to keep a stream of water constantly flowing 

 through the tank. Now, this is wrong. Goldfish are intended to live 

 in standing water, and should not be made accustomed to the con- 

 trary, as the reversing again of the character of the water often 

 proves fatal to them. 



v The proper way to keep fish is in pure standing water, to which 

 the necessary oxygen is supplied by the action of aquatic plants ; 

 these every dealer in fancy fish is compelled to keep on hand, if he 

 understands the principles upon which the aquarium is managed, and 

 if he wants to make the handling of fish a financial success. 



Aquatic plants, when in a healthy condition, exposed to the light, 

 consume the carbon in the carbonic acid gas which is produced by 

 the fish as refuse matter, and give off the oxygen, which in turn is 

 appropriated by the fish. This answers the question as to how many 

 fish can be kept in a certain tank, for it is easy to understand that a 

 locality favorable for the growth of plants will produce the greatest 

 amount of oxygen in the water. Large fish consume more oxygen 

 than small ones, so the proportion of fish to the tank must not be 

 greater than the supply of oxygen the tank can produce. Besides all 



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