[5] EAISING CAKP AND OTHER POND FISH. 1137 



about 60 spawning carp, and the edges of the pond are covered with 

 juniper brush. Spawning proceeds on a gigantic scale, and the brush 

 is soon entirely covered with spawn. As soon as the eye-dots become 

 visible in the eggs, which, according to the temperature of the water, 

 takes place in from two to six days, the brush with the spawn is packed 

 like other embryonated fish-eggs and sent to considerable distances. 

 Even after a journey of two days a great many young fish have been 

 hatched from such eggs. The fish are hatched after from three to 

 twelve days, and the pond swarms with innumerable little carp, whose 

 further development is intrusted to the care of the pond cultivator. 



For feeding carp and the fry of carp there are recommended ground 

 meat, kitchen refuse [slops], and the excrements of hogs and sheep. 

 In using artificial food care should be exercised, as the experience of 

 our most prominent pond cultivators has so far not been very satisfac- 

 tory, either as regards the feeding of fry or of older carp. 



Raising- perch-pike in ponds. — Mr. Eeuter, superintendent of for- 

 ests at Sielidichum, district of Guben, has been very successful in es- 

 tablishing artificial spawning places in lakes in which perch-pike had 

 hitherto not propagated. I, 'as well as Al. von Gostkowski, in Gali- 

 cia, have in the same manner raised perch-pike in ponds. A full de- 

 scription of Gostkowski's establishment has been given by Professor 

 Nowicki, of Cracow, in the circulars of the German Fishery Associa- 

 tion for 1883 [pp. 9-12 and 20]. ' The Galician pond has an area of 13 

 hectares [32 acres], and mine one of 11.5 hectares [28 J acres]. At a 

 depth of 1 meter [39.37 inches] and more, jplaces of considerable extent 

 are covered with coarse gravel and stones, and here and there some 

 heaps of stones are piled up. l^Tear to these there are placed tree tops 

 having many branches, which are cut just above the surface of the 

 water. The gravel is cleaned every year, and the pond is allowed to 

 lie dry as long as possible. In 1882 Gostkowski stocked his pond with 

 9 perch-pike and a number of small fish as food for the perch-pike, and 

 in autumn he caught 120,000 young perch-pike measuring from 5 to 10 

 centimeters [2 to 4 inches] in length ; but many of the fish had no 

 doubt escaped from the pond before he could catch them. 



At Wittingau perch-pike have often spawned in deep tanks which 

 constantly had a good supply of water. It may, therefore, be presumed 

 that they will do the same in small ponds, if these are sufficiently deep, 

 are naturally or by artifical means, as described above, adapted to 

 spawning, and contain suitable food for the perch-pike. In ponds ar- 

 ranged in this manner the American black perch can also be raised. 



Stocking^ of lakes and rivers with the fry of fish which 

 spawn in summer, obtained from raising-ponds. — In the same 

 manner the fry of bleak, tench, crucians, and other cyprinoids, as 

 well as of perch, can be successfully raised in large numbers in ponds 

 with soft bottom ; and the fry of perch-pike in ponds with sandy and 

 gravelly bottom. We have seen that a properly constructed spawn- 

 H. Mis. 67— 72 



