154 [PISH CULTURE 



batK, an'd perhaps tHe number in eacH trough 

 be reduced. In fact, after the fish have been 

 feeding well, there should be a thinning out be- 

 fore any sign of disease or undue uneasiness 

 develops. A trough filled with fry will be 

 greatly overcrowded by advanced fry after a 

 fortnight. The extent of the thinning will de- 

 pend of course on the number of fry that were 

 first put in the troughs. This must be left 

 wholly to the judgment or experience of the 

 fish-culturist. It might be said that where close 

 attention is paid to the health of the advanced 

 fry a much larger number can be carried in a 

 trough than some people suppose. 



Not many years ago the average fish-culturist 

 would hesitate to carry more than 15,000 ad- 

 vanced fry in a trough in which the same man 

 to-day would not hesitate to carry over 30,000, 

 or if driven to it, 40,000, and bring them through 

 successfully. While this is true, it is not ad- 

 visable to carry more than 15,000 or 20,000 

 advanced fry in a twelve-foot trough, nor is it 

 advisable to go far below the smaller number 

 mentioned, because there is less likelihood of 

 all the food that is given out being devoured, 



