ADDITIONAL NOTES ON REARING THE CHANNEL 

 CATFISH, ICTALURUS PUNCTATUS. 



By Austin F. Shira, 

 Director, U. S. Biological Station, Fairport, Iowa. 



Last year a paper was prepared for presentation before this 

 Society giving in considerable detail the results obtained in rearing 

 the channel catfish in one of the ponds at the Fairport Biological 

 Station. As these results constituted the first detailed record 

 of the breeding of this fish in ponds, you will be interested in a 

 brief account of the supplemental work done this year. 



It was very unfortunate that the conditions last year neces- 

 sitated the drawing of the pond to determine whether or not 

 the catfish had spawned. In order to avoid this, most of the 

 kegs to be used as nests this year were provided with an opening 

 in the side about 7x5 inches, with a closely fitting hinged cover, 

 so that when placed in a horizontal position in the pond, the 

 interior could be examined by simply raising this cover. All 

 kegs except a few buried in the bank were securely fastened to 

 posts so that little disturbance resulted when examination was 

 made. Twenty kegs in all were placed in the pond, fifteen of 

 which were provided with side openings and covers. Three 

 without openings were placed in a horizontal position in the pond 

 bank with the mouth outward. 



Several of the kegs were placed with the top within a foot of 

 the water surface. As the water in the pond became clearer 

 with the advance of the season, the interior of the kegs so placed 

 could be observed without great difficulty from the pond bank 

 when the covers were raised. On examining the deeper kegs, 

 however, it was necessary to use a water-glass. 



The brood stock numbering 40 individuals was placed in the 

 pond May 23, 1917. From July 1 until after the spawning season 

 the pond was subjected to frequent observation by the Super- 

 intendent, Mr. H. L. Canfield, and others. 



The first eggs were discovered July 12 in one of the kegs 

 placed within a foot of the water-surface. The nest was again 



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