SUCKER 



wishes to raise and stock accord- 

 ingly. The following table shows 

 the relation between the number of 

 fish produced in some Minnesota 

 sucker ponds and the size of the 

 fish at 60 days: 



These values may not hold true 

 in other areas, so each dealer will 

 have to study his ponds and de- 

 termine the prevailing relation- 

 ship. Of course, the stocking rates 

 necessary to produce certain num- 

 bers of fish will vary with each 

 pond according to the survival rate 

 that exists in that pond. 



The dealer who knows these re- 

 lationships for his ponds will be 

 able to stock some ponds lightly 

 to produce bait for midsummer. 

 Ponds stocked moderately will 

 produce the same size bait for late 

 summer, and tliose stocked heavily 

 will produce small fish that can be 

 held over winter for the early 

 summer season in the following 

 year. 



Operator that do not know the 

 stocking requirements of their 

 ponds well enough to build a grad- 

 uated series of populations that 

 will produce pike-bait sized suck- 

 ers during the entire fishing season 

 can adjust the pond populations 

 by moving fish from one pond to 

 another. By a system of periodic 



test nettings, the dealer can deter- 

 mine the growth rate of the fish 

 in each pond. By moving fish from 

 one pond to another, he can re- 

 lease some populations for faster 

 growth and can crowd others for 

 slower growth. 



In actual practice, the operator 

 tries to obtain the desired minnow 

 population in each pond by regu- 

 lating the stocking rate, and then 

 compensates for errors in judg- 

 ment and seasonal variations in 

 the survival rate by moving fish 

 from one pond to another. When 

 this program is used in conjunc- 

 tion with an overwintering pond, 

 a year-round supply of pike-bait 

 sized suckers can be produced. 



Fertilizing sucker ponds 



As most natural ponds produce 

 enough water fleas to feed all the 

 suckers the pond will hold, fertili- 

 zation is usually not necessary and 

 should be avoided whenever pos- 

 sible. A number of Minnesota 

 ponds have been operated for 6 or 

 7 years without fertilization and 

 are still producing good crops of 

 suckers. Suckers seem to grow 

 faster and more consistently when 

 feeding on chironomid-fly larvae 

 than when feeding on water fleas. 

 If the fish in a pond are growing 

 very slowly, the pond should be 

 fertilized with barnyard manure 

 or dried sheep manure to increase 

 the number of chironomids in the 

 bottom muds (see Fertilizing the 

 Pond, p. 24). 



Commercial inorganic fertilizer 

 should be used sparingly on north- 



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