PROPAGATIOjST and distribution of food fishes, 1921. 49 



The number of landlocked salmon eggs taken from Green Lake 

 represents an average season. Pound nets were set at the mouth of 

 Great Brook as usual, and 87 female and 49 male fish were taken, the 

 first fish entering the trap on October 14 and the last on November 

 19. Eggs to the number of 220,300 were secured, of which 70,000 

 were shipped to applicants. From the remainder 122,120 fry were 

 hatched and distributed. 



Of the 317,200 e^gs obtained at Grand Lake Stream 115,000 were 

 shipped to other points and 184,400 were retained for parent waters. 

 To the unseasonably warm weather, which continued through tho 

 late fall, and the consequent high- water temperatures the delayed and 

 prolonged run of spawning salmon is attributed. Spawning fish 

 were still being taken in small numbers daily, when a sudden tem- 

 perature change, with danger from ice, made it necessary to dis- 

 continue operations. The adult fish taken this season were of a 

 larger average size than is usual at this point. Several specimens 

 weighing 6 and 7 pounds were taken, yielding an average of 1,600 

 eggs per fish. During July and August 79,000 fingerling salmon 

 carried over from the previous year were liberated in (irand and 

 Dobsis Lakes. 



The work addressed to the propagation of smelt met with a fair 

 degree of success. From the 8,000,000 eggs obtained 7,000,000 fry 

 were hatched and liberated in local waters and 600,000 eyed eggs 

 were shipped to applicants. Practically all of the eggs were ob- 

 tained this season from natural spawning, the adult fish l)eing con- 

 fined in troughs until this function was performed, after which they 

 were liberated and the eggs transferred to hatching jars. Compara- 

 tive tests of this method of obtaining eggs as against artificial 

 stripping seems to prove the superiority of the former method. Of 

 150,000 eggs taken by artificial stripping only about 15 ])er cent pro- 

 duced fry, while the percentage of hatch obtained from natural 

 spawning was 95. It was noted, however, that the best results were 

 obtained from fish that were about ready to spawn when taken. 

 When lield in confinement for more than 36 hours prior to spawning, 

 eggs of a poor quality resulted. In one instance a trough in wliich 

 approximately 500,000 eggs had been deposited was left undisturbed 

 for observation after the removal of the adult fish. On the fourth 

 day the eggs showed the effects of smothering, this condition, which 

 is well known to fish-culturists. being brought about by improper 

 aeration of the water. The dam at the outlet end of the trough was 

 raised, thus subjecting the eggs to a more rapid flow of water and 

 relieving the dangerous symptoms. These eggs completed incuba- 

 tion in 14 days, with a mean water temperature of 55.5'' F., as 

 against 20 to 27 days for the eggs incubated in Downing jars, with 

 a mean water temperature of 46^. 



In addition to the species already mentioned, brook-trout eggs 

 to the number of 788,860 acquired by purchase from commercial 

 dealers and 50,000 rainbow-trout eggs transferred from the bureau's 

 Virginia station were received during the year. Fifty thousand of 

 the brook-trout eggs were reshipped to the Grand Lake Stream sub- 

 station. P^rom the eggs of that species retained at Green Lake 

 60H.050 fry wore distributed. The rainbow-trout eggs underwent a 

 rather heavy loss during incubation and produced only 26,000 fry. 



