SOME EXPERIMENTS ON THE ARTIFICIAL EX- 

 PRESSION AND FERTILIZATION OF 

 GOLD FISH 



BY JHRUY ]{. BERKHOUSE, SUPEIUNTEXDENT OF THE PENNSYL- 



VAXIA STATE FISH HATCHERY, TORRESDALE. 



PHILADELPHIA. 



The Department of Fisheries of the Commonwealth of Penn- 

 sylvania rears gold tish for the nse of public schools, public in- 

 stitutions and public parks, but not for private applicants. At 

 the hatchery under my charge at Torresdale, Philadelphia, I 

 handle principally the common gold fish and to a limit<_'d ex- 

 tent, Japanese three tails. From autumn until early spring the 

 adult gold fish of both types are kept in a large triangular pond 

 and in the spring the three-tailed fish are removed to a smaller 

 ])<iii(l. The regular practice has been to have the gold fish of 

 l)()lli types deposit their eggs on the roots of water hyacinth, the 

 phnits containing eggs l)eing removed every morning to small 

 ])()nd!< having no fish of any sort, and the eggs allowed to hatcli 

 naturally. 



IMu-ing the winter of 1907, my chief. Commissioner ^Fee- 

 liaii. directed that when the spawning jjcriod arrived 1 should 

 make some experiments in the artificial expression and fertiliza- 

 tion and hatching of gold fish eggs. This I did in the latter 

 l)art of May and beginning of June, 1908, being perfectly suc- 

 cessfid in artificially taking the eggs and fertilizing them and 

 succei'ding in hatching more than (iO jter cent. I used three 

 females of tlie common gold fisli and a like number of males 

 I |)i-ess('(l the t'ggs from tlu' female and the milt from the male 

 in ])recisely the same manner as from a brook trout. Both the 

 eggs and the milt flowed with perfect freedom, just as freely 

 in fact as eggs and milt from brook trout. 



Before taking my first fish ! dipjied the i)an in the water, 

 but instead of draining it oft' as is usual in the dry method, I 

 left a small (|uantity of water on the bottom, just enough to 

 cover it but not enough to bury the eggs. After taking the eggs, 



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