REPOET OF COMMISSIONER OF FISH AND FISHERIES. 61 



four years caused a heavy mortality. Efforts were made to check the 

 disease, but without success, until the fish were again transferred to 

 the earth ponds. Experiments conducted at this station prove that 

 it is impossible to hold adult brook trout in the 80-foot wood-lined 

 ponds, while there seems to be no difficulty in holding the same fish 

 in the larger ponds with natural earth embankments. 



From 257 ripe female brook trout 214,000 eggs were secured, or an 

 average of 833 per fish. Of this lot of eggs 50,000 were shipped to 

 applicants and 100,000 were hatched, but the fry were a very inferior 

 lot and only 65,000 were distributed. The poor quality of the fry is 

 attributed to the diseased condition of the parent fish. From the 

 Spearfish and Leadville stations 250,000 brook -trout eggs were 

 received, and 285,000 fry were hatched from the eggs received from 

 all sources. Of these, 189,000 were distributed during the spring and 

 96,000 were held for fall distribution. 



The 75,000 rainbow-trout fry on hand July 1 were carried until fall, 

 when 69,000 were distributed and 3,000 held for brood stock. The 

 spawning season of the rainbow trout extended from December 10 to 

 March 21. The brood stock of rainbows consisted of 3,980 three and 

 five year old fish, which were in excellent condition, having been held 

 in the large stock ponds the greater part of the year. Out of this lot 

 1,296 ripe females yielded 1,247,100 eggs, or an average of 963 per 

 fish. Of the total number of eggs secured 1,007,190, or 80 per cent, 

 were eyed. Of this number 525,000 were shipped on assignment and 

 182,190 hatched. Of the fry thus obtained, 211,000 were distributed 

 and 128,000 are being held for the fall distribution. 



At the beginning of the year there were on hand 10 adult Loch Leven 

 trout. During the month of November 8 ripe females produced 8,000 

 eggs. From this lot of eggs 6,000 fry were hatched, 3,500 of which 

 are on hand at the close of the year. 



There were also received from other stations in good condition 

 10,000 quinnat-salmon eggs, 10,000 landlocked-salmon eggs, 50,000 

 lake-trout eggs, 50,000 steelhead-trout eggs, and 100,000 grayling eggs, 

 which produced strong, healthy fry, and these fry were distributed 

 on assignments. 



The food used for the brook and rainbow trout fry that were reared 

 to fingerlings consisted of beef livers and mill shorts, boiled in vary- 

 ing proportions, according to the age of the fish. Live food collected 

 from streams in the vicinit}" of the station was also used to some extent. 



During the month of September the rock-bass ponds were drawn, 

 and the young fish, numbering 11,150, were transferred to troughs in 

 the hatchery, where they were held without loss until distributed. 

 The stock of adult rock bass on hand at the beginning of the year num- 

 bered 235, but this number was increased by the addition of 15 adults 

 collected from streams near the station. These fish were seen spawn- 

 ing in Ma}", and the first fry were discovered on June 20. The indica- 

 tions are that the crop of young from this brood stock will be large. 



