78 FISH CULTUEE 



there should be a large number of spawning- 

 ponds of small size, each large enough to hold 

 not more than five fish, three females and two 

 males. They must also be very shallow so that 

 the water may be warmed rapidly by the sun. 

 Such ponds need not be more than 20 feet long, 

 and eight or ten feet wide. Eaising-ponds for 

 advanced fry, fingerlings and yearlings, must 

 of necessity be much larger, and somewhat 

 deeper than spawning-ponds. They should not, 

 however, be of so great an area that they can not 

 be easily seined, and the fish handled quickly 

 and thoroughly ; but they must be large enough 

 to carry safely a number for at least one year, 

 preferably two. 



To facilitate growth, the water should be 

 moderately warm, mostly shallow, and the ponds 

 supplied with an abundance of aquatic vegeta- 

 tion. A large volume of water is not essential, 

 but enough to insure proper aeration and to pre- 

 vent too high a temperature is necessary. Con- 

 trary to widespread belief there can be an ex- 

 cessive water-temperature, even for carp. 



Eudolph Hessel, in his work "The Carp and 

 Its Culture in Eivers and Lakes and Its Intro- 



