CONTROLLING THE MOVEMENTS OF FISH 



By W. O. Buck 



The essentials of fish culture are three: food, water and 

 control. Indeed, since everything alive needs food and water, 

 mention of these might be omitted and the assertion made 

 that the essential of fish culture is control. 



We realize the need of regulating water-supply for the 

 purpose of preventing interference, of things animate and 

 inanimate, with our fish from the egg to the adult stage. 

 Attention is invited to the equally urgent need of controlling 

 their movements. 



To catch adult fish we study their habits and pit our wits 

 against theirs. Even when we seine them this is partly the 

 case, though it is then more a question of main strength and 

 stupidity, the fish being supposed to furnish the stupidity, 

 although it is to be feared they are not always allowed a 

 monopoly of it. And here is a point at which improvement 

 may be made. Wherever it is at all practicable the fish 

 should be led to go where they are wanted rather than 

 dragged thither. 



It is unnecessary to expatiate on the disadvantages of 

 seining fish ponds because that is realized. The suggestion 

 is that we get at some better method, instead of plodding 

 along the. same old wrong path. When eggs are hatched in 

 jars the fish swim over of their own accord to the collecting 

 tanks and are held by screens. Most fish culturists will re- 

 call the thrill of horror with which they have at some time 

 or other found this literally true; that is, the fish were held 

 by the screens instead of by the tanks. Here we start righl 

 by allowing the fish to follow their impulse to go with the 

 current and should go further and hold them where we 

 want them by offering no road out. It is not sufficient to 

 provide the road and blockade it with a screen. The screen 

 being a necessary evil should have as large a surface and as 



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