SOME IMPORTANT BAIT FISHES 



fourth year and males their fifth. 

 Creek chubs are not long-lived fish, 

 rarely exceeding 6 or 7 years. 



Stocking rates. — Recommended 

 stocking rates calculated on a the- 

 oretical basis derived from observa- 

 tions and studies conducted in 

 Michigan may not be entirely sat- 

 isfactory for all types of raceways. 

 It is believed, however, that a brood 

 stock should contain more females 

 than males (approaching a ratio of 

 2 to 1 or 3 to 2). Furthermore, 

 each female in stock composed of 

 3.5- to 7-inch fish should be pro- 

 vided with 1.5 square feet of spawn- 

 ing area for egg deposition, and 

 each female from a gi'oup composed 

 of 4- to 8-inch chubs, 2 square feet 

 of area. In calculating the square 

 feet of available spawning area in 

 a raceway, the margins along the 

 banks (about 3 inches on each side 

 of the stream) and any areas used 

 for refuge zones or current deflect- 

 ing structures should be omitted. 

 Generally, about one-fourth of the 

 total area will be taken up by these 

 structures. 



To illustrate, let us suppose that 

 an operator had a raceway 200 feet 

 by 4 feet, and wished to determine 

 the number of breeders it would ac- 

 commodate. Assuming that one- 

 fourth of the total area would be 

 occupied by the banks, refuge zones, 

 and other structures, he would have 

 to make his calculations on the re- 

 maining 600 scjuare feet of stream- 

 bed. If 3- to 7-inch females were 

 used, about 400 of these and 200 

 males would be required if a sex 

 ratio of 2 to 1 were established, or 



about 266 males if a 3 to 2 ratio were 

 followed. If 4- to 8-inch females 

 were used, 300 would be needed 

 with the corresponding ratio of 

 males. The mortality rate of adult 

 creek chubs during the spawning 

 season has been exceptionally high, 

 sometimes amounting to as much as 

 75 percent. To be assured that an 

 adequate supply of adult fish will 

 be available each spring, provision 

 should be made whereby a new 

 group of fish will be maturing each 

 year. 



Results from creek-chub studies 

 in Michigan indicate that with a 

 fair amount of success in fish cul- 

 ture, about 800 fry may be expected 

 for every female creek chub intro- 

 duced in a spawning raceway. In 

 Ohio, each female introduced into 

 a spawning raceway in 1941 gave a 

 return of about 400 salable fish, and 

 in 1942 about 450. Since we have 

 some idea as to the spawning needs 

 of 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 

 necessary to realize a predeter- 

 mined production. 



There was considerable difference 

 in the size range of the fish pro- 

 duced in individual ponds. Ponds 

 that had a high production con- 

 tained smaller fish than those of low 

 production. In ponds where the 

 average length of the chubs was 

 about 2 inches, the number of fish 

 per pound was 300. In other ponds 

 where the fish averaged about 31/^ 



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