53 



salable fish, and in 1942, about 450 salable fish per 

 female. As we have some idea as to the spawning needs 

 for the female chub and can roughly calculate the 

 number of females which will satisfactorily stock a 

 specified raceway, a crude estimate can be made as to 

 the number of females and the size of the raceway which 

 will be necessary to realize a set production figure. 

 As a possible aid to the creek-chub producer in 

 estimating the number of chubs per pound, table 8 is 

 presented. 



Table 8. — Creek chubs per pound at various lengths- 



1/ 



i/ These figures are derived from representative 



samples of fish taken from 8 ponds used in creek-chub 

 studies in Mich. 



Disease and parasite control 



When minnows are raised in ponds under hatchery 

 cpnditions, they can be expected to suffer from many 

 of the diseases of hatchery fishes. For this reason 

 it seems wise to mention some of these diseases, 

 parasites, and predators, and to outline briefly a 

 program for prevention and cure. Moreover, diseased 

 and ailing fish are often collected by unsuspecting 

 dealers, or the fish may become fungused from improper 

 handling in the nets or tanks. 



The best method of disease control in a hatchery 

 is prevention. Minnows that are handled properly and 

 that are adequately tempered before handling will 

 usually be free from disease (p.72 ). 



780060 O - 48 - 8 



