78 U. S. BUREAU OF FISHERIES. 



the small numbers of such fish produced become of importance in 

 view of the heavy demand for them as compared with the limited 

 facilities for their propagation. The station's output of pond fishes 

 for the fiscal year 1922 aggregated 50,675. 



LOUISVILLE (KY.) STATION. 

 [C. W. BuRNHAM, Superintendent.] 



The aggregate output of this station for the year was m excess 

 of 600,000 fry and fingerling fish of the following species: Large- 

 mouthed black bass, small-mouthed black bass, rock bass, sunfish 

 (bluegill), and yellow perch. Special attention has been given to 

 the propagation of the small-mouthed black bass, and there has been 

 a gradual increase in the output of that species for the past three 

 years. During this fiscal year 345,000 advanced fry and fingerlings 

 of this species were produced and distributed to applicants. It is 

 of passing interest to note in connection with this work that 143 

 small-mouthed black bass adults from Lake Erie, which were placed 

 in spawning ponds at the station just a few days before the mating 

 season, produced 114,000 fry, although during the previous year 

 adult fish from the same source were placed in the ponds in October 

 and failed entirely to spawn. The brood stock of 100 large-mouthed 

 black bass, though apparentl3^ in excellent condition, was practi- 

 cally nonproductive, only one school of fry being observed. This is 

 probably attributable to the advanced age of the brood stock. The 

 work concerned with the rock bass and the sunfish was successful 

 to the extent that the numbers of those species produced compare 

 favorably with the output of previous years. The stock of yellow 

 perch, consisting of 315 small-sized adults, produced 50,000 fry, 

 and because of the unsatisfactory returns from these fish over a 

 period of several years, all of them were liberated in the Ohio River 

 at the end of the spawning period. As the yellow perch appears to 

 be a highly prized fish in the locality, 200,000 eggs of this species 

 were transferred to the Louisville station from the Potomac River, 

 and a satisfactory percentage of fry was obtained from them for 

 distribution. 



MAMMOTH SPRING (ARK.) STATION. 

 [W. S. Vincent, Superintendent.] 



The work of improving the station pond system, which has been 

 in progress for the past two years, was carried forward as time 

 permitted. Such work included remodeling of the standpipes, con- 

 struction of kettles in some of the ponds, and the formation of 

 one large pond by throwing four small ponds of the old system to- 

 gether. The extreme eastern section of the levee, which runs par- 

 allel to the creek, was strengthened by riprapping that portion that 

 is most exposed to the ravages of drift during high-water periods; 

 and, as a precaution, a ditch 1| feet wide by 2 feet deep was cut 

 in which to start the wall, thus insuring the new rock work against 

 slipping. As the base of the new construction is from 8 to 10 feet 

 wide and from 3 to 5 feet in width at the top, it is believed it will 



