8 V. S. BUREAU OF FISHERIES. 



EXPERIMENTAL FISH CULTURE. 



The largest pond-culture production of buffalofish recorded has 

 been obtained at the fisheries biological station, Fairport, Iowa, in a 

 pond measuring 0.846 acre in surface area. From eight adult buffalo- 

 fish held in this pond, which was afforded an artificial flood similar 

 to the natural spring flood of rivers of the Mississippi drainage, 

 98,000 fingerling buffalofish from 2 to 5 inches in length were raised. 

 The computed weight of these 98,000 fish was 1,753.5 pounds. The 

 growth of the fingerling was not derived entirely from the natural 

 food of the pond in which they were bom, since many obtained a 

 chance entrance into an adjacent pond where there was a less 

 crowded condition. The production, however, is exceptionally large 

 and noteworthy for any species of fish in a pond. 



In recent years it has been learned by experiment that an artificial 

 rise in the level of the water of buffalofish ponds at the time of spawn- 

 ing is a desirable factor in obtaining a large production of fry. The 

 rise is meant to simulate the natural rise of the river during which 

 the buffalofish in nature spawn. Experiments with controlled ponds 

 indicate that the rise is not entirely necessary but that it is especially 

 to be desired. The usefulness of the " artificial flood " in the pond 

 culture of buffalofish of both species — the small-mouth or current 

 buffalofish, Ictiohus huhalis, and the stub-nose or big-mouth buffalo- 

 fish, Ictiohus cyprinella — has apparently been demonstrated. 



After several years of successful experimental pond propagation 

 of the buffalofish, H. L. Canfield has prepared a concise account of 

 the information at hand in the care and feeding of buffalofish in 

 l^ond culture.^ It includes observations on space requirement of 

 adult and fingerling fish, handling of ponds in buffalofish culture, 

 relation of water stage and temperature to production, and observa- 

 tion on natural and prepared food and feeding. 



Pursuant to the purpose of maintaining as close and helpful a 

 relation as is possible between the scientific inquiries of the bureau 

 and the practical fish-culture work, a scientific assistant was detailed 

 to spend the greater part of the year at a fish hatchery in observing 

 the fish-cultural methods employed, conducting experiments with 

 alternative methods, and making studies of the fish and the condi- 

 tions of their propagation and rearing. D. R. Crawford, selected for 

 this detail, visited the Erwin (Tenn.) station in the fall of 1921 and 

 remained there until the close of the fiscal year. 



Stripping the fish with belly down and applying pressure only 

 back of the ventral fins was tried out with results justifying the 

 conclusion that the established method (holding tlie fish belly up 

 under the left arm and passing right hand over abdomen and sides 

 from head to vent), when carefully and skillfully applied, is better 

 because of the lesser period of time during which the fish is subject 

 to the operation. Injuries when manifested are probably due chiefly 

 to lack of training, skill, or care on the part of the spawn taker rather 

 than to defects of method. Test of different frequencies of stripping 

 gave inconclusive results, but it appeared that two-day intervals were 

 too frequent at the beginning though not at the height of the season ; 

 different lots of fish vary in the rate of maturing of the eggs and 



» Care and Feeding of Buffalo Fish in Ponds. By H. L. Canfleld. U. S. Bureau of 

 Fislieries Economic Circular No. 56. Issued December 13, 1922. 



