PEOPAGATIOX AND DISTRIBUTION Or FOOD FISHES, 1921. 61 



thej^ are included in the station's output. The experimental work 

 connected with the spawning of the rainbow trout will be continued 

 over a series of years, the operations next year to be conducted at 

 Erwin, Tenn. With this end in view 416 of the adult fish involved in 

 last season's work have been transferred to Erwin. 



The output of brook trout from the station was reduced to negli- 

 gible proportions by an apparently infectious disease which attacked 

 the fry shortly aftev incubation was completed. Eggs from commer- 

 cial hatcheries to the number of 274,000 were received, but because 

 of this trouble only 30.000 fry were available for distribution. The 

 output of this species also included 1,900 No. 4 fingerlings carried 

 over from last year's hatch. 



The largemouth black bass, usually prolific at this station, pro- 

 duced very few young. The l)rood stock consisted of 194 fish, and 

 during April 60 nests were counted in one pond. A sudden drop 

 in temperature had the effect of destroying all the eggs deposited, 

 and the few fry produced were the result of a later si)awniiig. The 

 distribution o^ rock bass consisted of 14.060 fingerling fish Nos. 2 

 and 3 produced from 230 brood fish, while 10,325 sunfisli comprised 

 tlie outjjut from a stock of 200 breeders of that species. Adult 

 crappie to the number of 47 were carried through the year, but so 

 far as could be ascertained the fish did not spawn, nor have they been 

 known to take food. Of the 20 catfish transferred from the Cold 

 Springs (Ga.) station last year only 5 remained at the end of June, 

 1021. because of tlie ratlier dense growth of vegetation in tlie pond, 

 in which they were carried nothing could l^e learned as to any pos- 

 sible spawning activities. A consignment of 500,000 pike-perch eggs 

 received from the S wanton (Vt.) hatchery Avas successfully incu- 

 bated, and the resulting fry were planted in New River, Va. 



With the view of increasing the efficiency of the work at the 

 Wytheville station, particularly in connection with trout propaga- 

 tion, further repairs and improvements were made in addition to tlie 

 new water-supply system installed last year. The more important 

 features of this improvement were the demolition of the old wooden 

 building used as a nursery and the construction of a new two-story 

 building 56 by 36 feet. The building is of concrete to the window 

 sills of the second story and of frame construction above that. It 

 will contain 60 standard troughs — 20 on the first floor supplied with 

 brook water and 40 on the second level — which may use either brook 

 or spring water, or a mixture of both as may be desirable. An en- 

 larged settling tank and filter are also in process of construction for 

 the correction of the turbid condition to which the spring water is 

 subject for long intervals after heavy rains. 



WORK OF POND FISH-CULTURAL STATIONS. 



Climatic conditions play an important part in all branches of fish 

 culture, but the success or failure of a season's work at a pond-cul- 

 tural station is peculiarly susceptible to temperature changes in the 

 spring. If the weather in the early spring is warm, the spawning 

 activities of the fish, particularly the basses, are hastened. Should 

 this condition be followed by a period of falling temperatures, it 

 inevitably Tesults in the desertion of the nests by the adult fish and 

 the loss of i)ractically all the eggs produced. 



