176 
BULLETIN OF THE BUREAU OF FISHERIES 
Winnipeg; it has been successfully acclimatized in the Potomac River. Relatively 
small, finely flavored, attractive in appearance, trim and gamey, it is esteemed by 
anglers as well as by commercial fishermen. It rarely exceeds 5 pounds in weight, 
though it may attain a weight of 10 pounds or even, according to Forbes and Richard- 
son, 15 or 20 pounds. It is the species of catfish principally taken at Keokuk. 
Although individually smaller than either the Fulton cat or the goujon, it is so 
much more numerous that it constitutes the bulk of the total catch of catfish. It is 
the predominant catfish in all sections of the river from Canton, Mo., to Lake City, 
Minn. 
There is no reason to suppose that the breeding of spotted cat is geographically 
localized. The fish was bred at Washington, D. C. (U. S. Commissioner of Fisheries, 
1894, p. xxxix; Worth, 1895, p. 96; U. S. Commissioner of Fisheries, 1912, p. 17), and 
in ponds at the Fairport (Iowa) station (Shira, 1917 and 1917b). There are also 
reports of breeding in Kansas (Wampler, 1895, p. 10), but in this case the identifi- 
cation of the species was not co nfir med. Although there are general statements in 
the literature regarding the breeding of spotted cats, we know of no recorded obser- 
Figure 14. — Spotted catfish, Ictalurus punctalus 
vations of breeding in nature. Examples containing large eggs have been collected 
at Fairport, and young were taken near Homer, Minn., in 1916, by Superintendent 
D. C. Booth of the United States Bureau of Fisheries. The observations at Keokuk 
that bear upon the breeding season were as follows : One fish with eggs in an advanced 
condition taken on set line near the power house, July 2, 1915; three with eggs in 
advanced condition seen in a market at Fort Madison, Iowa, June 2, 1916; two that 
seemed to have spawned recently seen in the Warsaw market, July 26, 1916; six exam- 
ples in similar condition seen at Keokuk, August 1, 1916. Small fish, probably 
yearlings, were taken near Keokuk on several occasions. 
The author in 1914 initiated experiments at Fairport in the pond culture of this 
species. Prompted by a chance observation of the nest of a catfish of another 
species found in an old pitcher in a lake in Michigan, he had 66 brood fish placed in a 
small pond having pieces of tile drain and nail kegs half buried in its banks below the 
water level. The water was roily much of the time and no signs of the fish were seen, 
but when the pond was drained in the fall nine young were obtained. The experiment 
was repeated the following year with almost identical result, seven young catfish 4 to 8 
inches long being found in addition to the brood stock. It was evident that breeding 
had occurred each year, but the young had largely disappeared, probably devoured 
