586 U. S. BUREAU OF FISHERIES 
pond banks, and painting buildings and equipment. These additions 
materially increased the capacity and efficiency, and enhanced the 
appearance of the property. 
The Las Vegas (Nev.) unit reports a substantial increase in the 
output, even though weather conditions were extremely unfavorable 
during the bass-spawning season. The recurrence of high winds and 
extreme temperature fluctuations caused large numbers of the bass to 
leave the nests after the eggs were deposited. The consequent delay 
in completion of spawning resulted in retarded development which 
postponed much of the distribution until after June 30. Sunfish pro- 
duction was very satisfactory. Bass production was 7,000 and bream 
20,000, per acre. A shortage of water is reported, due to decreased 
flow of the two artesian wells. 
The cooperative substation at Mullan, Idaho, received the major 
portion of its eggs from the Idaho Fish and Game Department. 
Trout began spawning much earlier in this region than last year, and 
better results are expected from all lots of eggs handled. Rainbow 
and blackspotted trout were propagated. All fish were planted in 
Shoshone County, in the Coeur d’Alene and St. Joe National Forests, 
by the Idaho Fish and Game Department in cooperation with the 
U.S. Forest Service and the C. C. C. 
The Hagerman (Idaho) station made some changes in fish-cultural 
practices. Feeding formulas and methods were modified with the 
rainbow-trout brood stock, which resulted in a larger take of superior 
eggs. Although fish resulting from domestic eggs show a larger loss 
‘in the sac stage than those from wild eggs, the growth of the former 
is decidedly more rapid. More than 1% million fingerlings and adults 
were planted during the year and there are on hand slightly more than 
2% million fingerlings and one-half million eggs. Rainbow trout is the 
only species held as brood stock, but brook and blackspotted trout 
and sockeye salmon (landlocked) eggs were received by transfer and 
hatched. 
The Sun Valley (Idaho) substation was operated from April 1 to 
May 18 for the collection of rainbow-trout eggs. A W. P. A. project 
included the grading of 1 mile of road to connect with the county road 
with 2 bridges. The W. P. A. also completed 3 new rearing ponds 
which have a carrying capacity of one-half million fingerling trout to 
the 3-inch stage. Development of a 5-acre park is about 30 percent 
complete. 
The Salmon (Idaho) station propagated rainbow, brook, black- 
spotted, and golden trout. Rainbow-trout eggs were collected from 
Williams Lake, and the other species were received as eyed eggs. 
Although fewer green eggs were collected this year than last the 
resultant number of eyed eggs was only slightly less, since extra care 
exercised in the selection of spawners, fertilization, and transporting 
eggs to the hatchery resulted in an average of 90 percent eyed eggs 
as compared to an average of only 66 percent in 1939. 
The Bozeman (Mont.) station had an unusually successful year. 
The loss of fry and fingerlings was very small and growth was excellent. 
The 3-year-old rainbow trout brood stock spawned to a limited extent 
this year. Rainbow, brook, brown, and blackspotted trout eggs 
received from other Federal and State hatcheries, and 300,000 eyed 
Montana grayling eggs were received from the Yellowstone Park 
station. Hatching and feeding of this species proved successful, as 
