1114 EEPOET OF COMMISSIONER OF FISH AND FISHERIES. [14] 



Any one who, without ijroperly distinguishing the sexes, and without 

 selecting carj) of the proper size, simply places a number of carp in deep 

 ponds for purposes of propagation, as is unfortunately still done in 

 many places, need not be astonished if from numerous spawning carp 

 he only raises a few sickly young fish. 



From four to eight days after the eggs have been deposited, the youug 

 carp slip out of them and soon sport about in a lively manner among the 

 leaves of the aquatic plants. The small umbilical bag which they carry 

 with them from the egg is soon consumed, and the little fish will then 

 begin to hunt for infusoria, very young larvse of insects, crustaceans, &c. 

 The quantity of food, however, soon becomes to small for the enormous 

 number of young fish ; and, under ordinary circumstances, a very large 

 percentage perish very soon simply from lack of food, and the surviv- 

 ors do not grow as rapidly as would, be the case, if they hacl ample food. 

 The method practiced by Mr. Dubischon the estates of Arch Duke Al- 

 brecht near Teschen, is therefore to be strongly recommended. It con- 

 sists in gradually transferring the young fry raised in a small pond, and 

 kept in it for a short while, to numerous other i^onds, where they will 

 grow rapidly and suifer but few losses. The first transfer is made five 

 to eight days after the fish have been hatched. They are taken up 

 with fine gauze-nets, collected in a floating tank with a wire bottom hav- 

 ing very narrow openings, and thence are taken out in a small sieve, 

 holding about 1,000, and placed in the transporting vessels. The ponds 

 intended to receive these young fish are of the same character as the 

 spawning-ponds. Until they are stocked with fish, they should, if pos- 

 sible, lie dryj so as to be free from enemies of the young fish, and full 

 of fish-food. During the time that the young fry remain in the spawn- 

 ing pond proper — i. e., as long as they have their umbilical bag, and even 

 a few days longer — Dubisch counts 100,000 young fish to 3 hectares pond 

 area of ponds of the second class (the pond to which the fish are removed 

 from the spawning-pond proper). From data which he has furnished 

 to Mr. Von dem Borne, it appears that the fish grew several centimeters 

 in length in these ponds during a period of about four weeks, and de- 

 creased about 25 per cent, in number. They continued to grow well, 

 after they had again been transferred to another pond. The spawning- 

 ponds of the second class have previously been planted with some 

 kind of grass, which has been j)roperly harvested, after which they 

 should lie dry for some time before being stocked with fish. They are 

 stocked at the rate of 1,050 young fish per hectare, of which number 

 there should remain in autumn 1,000 fish weighing one-quarter of a pound 

 a ijiece. If these ponds are stocked with only 300 to 500 fish per hectare, 

 they are said to reach the weight of one pound in autumn. Supposing, 

 therefore, that in a spawning-pond proper of an area of 0.1 hectare a 

 spawner had deposited 100,000 eggs, and that the young fish hatched 

 from these eggs are distributed, after eight days, over a pond-area of 3 

 hectares, there would be 75,000 left after four weeks, which would be 



