USE OF FISH PITUITARIES TO INDUCE SPAWNING 

 IN CHANNEL CATFISH 



by 



Kermit E. Sneed and Howard P. Clemens 

 University of Oklahoma 



ABSTRACT 



Seventy -two pairs of channel catfish (Ictalurus punctatus) were induced to spawn in 

 glass aquaria by injecting fish pituitary into the females. Control of peritoneal lesions, infec- 

 tions, and adhesions, was anticipated by including 10,000 xmits of crystalline penicillin-G with 

 each injection. 



Spawning was induced by injecting acetone-dried pituitaries from carp, buffalofish, 

 flathead and channel catfish, and gar. Pituitaries from these various species differed little, 

 regardless of time of collection. The amount of pituitary material required to induce spawning 

 varied from 3 to 32 milligrams per pound of fish weight, given in from 1 to 28 injections, with 

 an average of 3. Most females required 3 injections at 2 milligrams per pound of body weight 

 every 24 hours. The period of time from the last injection to spawning varied from 2 1/2 hours 

 to 72 hours, but averaged 16 to 24 hours. 



In a recent paper (Clemens and Sneed, 

 1957) we pointed out the value of the chan- 

 nel catfish ( Ictalurus puntatus ) to the 

 warm-water fisheries of the United States 

 and described the behavior of this species 

 when induced to spawn by the injection of 

 fish pituitaries. Little information was 

 given concerning the methods employed. Now, 

 however, the accumulated data of 2 years' 

 worki' warrant a report on the method, which 

 appears to be suitable for large-scale com- 

 mercial operations. 



James W. Atz in a recent book (Pick- 

 ford and Atz, 1957) reviewed the literature 

 on induced spawning in fishes and stated 

 that the pituitary method of inducing fish 

 to spawn had been used on a commercial scale 

 in Russia and South America, but only exper- 

 imentally in the United States. 



Note . — This paper was coauthored by Kermit E. Sneed, 

 Research Institute, and Howard P. Clemens, Zoology 

 Department, University of Oklahoma, Norman. 

 Mr. Sneed's present address is U. S. Fish and Wildlife 

 Service, Bureau of Sport Fisheries and Wildlife, 

 Southeastern Laboratory, Marion, Alabama. 



1/ This investigation was conducted under the Saltonstall- 

 Kennedy Act for commercial fishery research. The 

 contracts are held by the Univeisity of Oklahoma Re- 

 search Institute . 



Recent interest in the catfishes as 

 a commercial food fish to be grown in the 

 ricefield reservoirs of Arkansas, Louisiana, 

 Mississippi, and Texas has increased the 

 need for more information concerning the 

 spawning of these fish in order to produce 

 sufficient numbers of fingerlings for stock- 

 ing. Since it is very difficult to induce 

 channel catfish to spawn in some hatcheries, 

 we have tried to find a simple method that 

 would ensure a sufficient supply of spawn 

 when needed to stock the hatchery. 



There are several advantages to in- 

 duced spawning in hatchery operations: (1) 

 The spawn can be obtained at a time conven- 

 ient and desirable to the f ish-culturist, 

 thus allowing him to plan his work and to 

 stock his waters according to a rigid sche- 

 dule. The injections to a gteat degree 

 eliminate the variables in the environment, 

 such as spawning areas, temperature, light 

 and other climatic conditions. (2) The 

 spawning period can be altered within rea- 

 sonable limits; i.e., earlier or later 

 seasonal spawning , or all spawn may be 

 taken in a shorter period. (3) Fish that 

 will not spawn naturally sometimes can be 

 induced to- spawn. (4) Culture ponds can 

 be stocked with eggs and fry that are more 

 uniform in age and size. (5) The trans- 

 mission of disease from brood stock to 



