PRACTICAL CARP CULTURE. 35 



and they are not fed they will only measure from two to three inches. 

 In smaller hatching ponds all the relations above hold good. The bottom 

 must be constructed on the same plan, plenty of shallow water about the 

 margins with deeper water to retreat too. The question of how many 

 good, healthful, growing fish can be raised in a limited area of water if 

 the margins are in good shape for spawning grounds and the temperature 

 is all right, resolves itself into a question of oxygen and food. 



The removal of the fry from the hatching pond, either for shipping 

 purposes or for transfer to the stock pond, must be done with the utmost 

 care. The water must be drawn off through the slatted or grated outlet 

 very slowly, that no fish may remain. in the mud, for if the pond is to be 

 again used for spawning purposes the larger fish remaining will consume 

 the food intended for the new hatch. The slightest injury to the young 

 fish in the breaking of the skin or knocking off of scales may result in 

 disease and death. 



In our Northern, Northeastern and Northwestern States the hatching 

 ponds should be shallower, with the greatest depth of water not to exceed 

 two feet and be used for the purpose only of hatching and rearing the 

 young the first summer. The pond should be drawn off in the fall and 

 the fry transfered to the stock pond. The reason for this is that with 

 water enough to successfully winter the fry in the hatching ponds in these 

 latitudes it would be difficult to get the water warm enough for the carp 

 to spawn. It would at least delay the time of spawning until late in June 

 or July, and the young would have but a short season for growth. The 

 earlier the spawning is done the better the opportunity for the fry to get a 

 good growth the first summer, which is a very important factor in their 

 development the second summer. With the exception of. these colder 

 sections of our country, the general rule will obtain for hatching ponds; 

 that is a large proportion of the area of the pond the water is to be shal- 

 low, from one foot deep to nothing, and plenty of vegetation in this part 

 of the pond, which should equal about three-fifths of the whole area, one- 

 half of the remainder should be from one to two feet deep and the other 

 one-fifth from two to four feet deep, and it will be safest and best to win- 

 ter the young fish in these ponds. 



THE STOCK POND. Its construction is the same in every particular as 

 that of the hatching pond, only that it is deeper and larger. The average 

 depth of the hatching pond Is about fifteen inches. The average depth of 

 the stock pond shonld be from twenty to twenty-four inches. The shal- 

 low and deep water may be divided in the same proportions as in the 

 hatching ponds, three-fifths of the whole area being from four to eighteen 

 inches deep, one-fifth from eighteen to thirty-six inches and the remain- 

 ing one-fifth from thirty-six to sixty inches, which will give an average 

 depth of about twenty-three inches. 



The stocking of these ponds generally takes place in the spring as 

 soon as the ice is gone and the fish begin their search for food. Owing to 

 the great climatic differences in portions of the United States it is dif- 

 ficult to set a definite time for this operation. Between Texas and Wis- 

 consin or Minnesota there could readily be a difference of six weeks or 



