[3] RAISING CAEP AND OTHER POND FISH. 1135 



soon as they are placed in the pond, provided that the temperature of 

 the water is at least 14P E. If this is not the case after a few days, 

 and if the water begins to be turbid, the fish may not spawn at all. If 

 the same fish, however, are placed in another spawning pond which has 

 just been filled, they will, as a rule, spawn at once. It is necessary to 

 have several spawning ponds and a reserve of several sets of spawning 

 carp, although they may be used only on rare occasions. 



Aftera few days thepondswarms with small carp. Dubisch thinks that 

 a spawner weighing 7 or 8 pounds produces 100,000, and one weighing 12 

 to 15 pounds produces 200,000 young ones. These are amply sufficient for 

 a farm having a pond area of 500 hectares [1,236 acres]. For spawning 

 carp the largest and best-formed fish are carefully selected from fish 

 of the same ' % because rapid growth is hereditary among fish. It is 

 important tL^c the young fish should grow as large as possible during 

 the first summer. It is therefore necessary that the carp should spawn 

 as early in the season as possible. 



Eaising-ponPS. — As the little fish grow larger their demand for 

 food inc^ases. Large fish, therefore, need a greater water area than 

 small fish in order to obtain sufficient food. Only when there is at no 

 time any lack of food will the fish develop in a favorable manner, and 

 will put the food which is supplied to the best possible use. After the 

 young fish have consumed the umbilical sac they commence to seek 

 food, and the pond soon becomes too small for them. If care is not 

 taken to supply more food, the numerous fry will disappear almost en- 

 tirely in a few days, dying from hunger. About five days after the fish 

 have been hatched they are taken out of the spawning pond and are 

 placed in raising-pond No. 1, so that, according to estimate, 100,000 

 young fish get 3 hectares [7^ acres] of pond area. 



The fishing of the fry is dooe in the following manner: The water of 

 the pond is either let off slowly through a fine wire grate (6 wires to 1 

 centimeter) [15 wires to 1 inch] while fishing is going on at the same 

 time, or the water is not let off, and the fry are caught with a gauze 

 dipper measuring 0.5 meter [20 inches] in diameter. To receive the fry 

 temporarily Dubisch uses a large seine floating in the pond with a high 

 wooden edge, and a bottom of exceedingly fine wire grating. Thence 

 the fry are dipped out with a smaller gauze dipper, measuring about 0.2 

 meter [8 inches] in diameter and placed in a spacious tin vessel, taking 

 out as near as possible by estimate 1,000 at a time. From the tin vessel 

 they get into the transporting can. This can has a double bottom, the 

 upper one of wire grating, the lower end of a tin tube opening between 

 the two bottoms, and its upper end a few centimeters above the lower 

 edge of the transporting can. When water is poured in the can it flows 

 off through the tube, and carrys away dirt and excrements which may 

 have accumulated underneath the wire bottom. Mr. MUhlbach, a tin- 

 smith of Neudamm, sells such cans at 13 marks [$3.09] apiece. The 

 raising-pond No. 1 has lain dry as long as possible, so that it may be 



