502 U. S. BUEEAU OF FISHEEIES 



have been even more rapid had it not been for the occurrence of 

 furimculosis, which has caused serious losses among the selected 

 fish. It is hoped that eventually it will be possible to develop a 

 strain of trout more resistant to this disease than the average fish, 

 but it is too earl}^ to predict how successful this attempt will be. 



As in i^revious years, a number of selected fish were mated, and 

 the progeny of each pair will be reared separately until it is de- 

 termined if they possess any points of superiority. In addition to 

 selecting such characters as fecundity, rapid growth, vigor, and re- 

 sistance to disease, a special attempt is now being made to develop an 

 early-spawning strain of fish. Such a strain would possess manj'' 

 advantages, especially in the extreme Northern States. During the 

 fall of 1931 eggs were taken from 56 pairs of selected fish. Several 

 of these showed an exceptionally high percentage of eyed eggs and 

 one 4-year-old female yielded 2,557 eggs, 97 per cent of which eyed. 



In this connection it is interesting to note that the average size 

 of fingerling brook trout at the Pittsford station has increased each 

 year from 1,630 grams per 1,000 fish in 1928 to 5,189 grams in 1931. 

 Of course, this increase in size is partially due to the use of better 

 ]"ations, but that the greater part is due to improvement in stock as 

 the result of selection is evident from a comparison of the experi- 

 mental lots fed beef liver as shown in the following table : 



Weight In Date 



grams per when 



Year 1,000 fish weighed 



1928 2,174 October 15. 



1929 2,893 September 24. 



1930 3,707 September 3. 



1931 4,421 September 3. 



We can not, of course, hope to increase the size of trout fingerlings 

 indefinitely, but there can be no question that by constant selection 

 of the brood stock and by the use of improved foods it will be pos- 

 sible to produce trout of catchable size in a much shorter time than at 

 present. 



LEETOWN STATION 



Construction work at the new experimental station at Leetown, 

 W. Va., was started in the spring of 1931. This station is located 

 on a tract of approximately 150 acres, watered by several springs 

 with a combined minimum flow of over 2,000 gallons per minute. It 

 is planned to operate this plant as a trout and pond station; but 

 owing to lack of funds for developing the property, it will be im- 

 possible to do any pond-cultural work at present. Eventually, how- 

 ever, there will be between 75 and 100 acres of ponds devoted entirely 

 to experimental work with warm-water fishes. 



The main building, which is designed primarily for a trout hatch- 

 ery, is now practically completed. This building is constructed of 

 native limestone and is approximately 125 feet long by 40 feet wide. 

 The middle section contains 60 standard hatching troughs on the 

 ground floor, with offices, library, photographic room, and storage 

 rooms on the second floor. Wings at each end of the building con- 

 tain the laboratories and a public aquarium. Immediately in the 

 rear of the main building is an old gristmill which has been re- 

 modeled to serve as a garage, carpenter shop, and meat room. A 



