PROPAGATIOlSr AND DISTRIBUTION OF FOOD FISHES, 1925 487 



authorities, the State purchasing the eggs from commercial fish-culturists and 

 distributing the fry by means of its fisheries car. The bureau's part of the work 

 comprises the incubation of the eggs and the care of the young fish produced 

 until tliey arrive at a suitable age for liberation in open waters. Such operations 

 during the past year involved the purchase and incubation of 1,041,000 eggs and 

 the distribution of nearly 1,000,000 fingerling fish. Seven hundred thousand 

 brook-trout eggs, received in exchange for those of other species, produced, in 

 round numbers, 450,000 fingerlings. These fish were distributed by the bureau's 

 force. 



Froin the brood stock of rainbow trout carried in the station ponds, 1,200,000 

 eggs were collected, the spawning season extending from November 10 to the 

 end of January. Of these, approximately 360,000 were shipped in the eyed stage 

 to applicants and to other stations of the bureau. From the retained eggs more 

 than 400,000 fingerling fish were produced and distributed, 63,000 being on hand 

 at the close of the fiscal year. The bureau recently undertook the propagation 

 of Loch Leven trout at this station with the view of providing a substitute for 

 the brook trout in many of the streams of West Virginia where that species was 

 formerly abundant but no longer thrives, owing to changed conditions. With this 

 plan in view, 150,000 Loch Leven eggs were forwarded to the station from the 

 Madison Valley (Mont.) field during the winter. They were of fine quality 

 and produced a large percentage of fry. Three thousand fingerling fish, part of 

 the results of a similar shipment in the preceding year, are being reared for a 

 future brood stock. 



An interesting and conclusive feeding experiment was conducted during the 

 spring. A lot of 15,000 rainbow-trout fingerlings was fed on beef heart and fish 

 meal mixed in equal proportions, while another lot, similar in every respect to 

 the first, was maintained on a diet of beef heart solely. When undertaken it 

 was the intention to prolong the test for 60 days, but by the end of the forty- 

 seventh day the fish in lot 1 had become so emaciated and the daily losses were 

 so heav}^ that it was necessary to abandon the experiment. In the course of the 47 

 days the increase in the weight of the first lot was only 5.075 pounds, and 1,721 

 of its number had perished. The control lot had gained 12.3 pounds and the 

 entire loss for the period was only 288 fish. Practicallj^ no loss occurred in the 

 first lot until the end of the thirtieth day, after which time the rate of mortality 

 increased rai^idly, and when the test vv^as discontinued it had attained the alarm- 

 ing total of 250 fish per day. 



x\nother feeding experiment was made with the view of noting its effect on the 

 quality of the eggs obtained from the brood stock. For some time prior to the 

 spawning season a number of adult rainbow trout were maintained on a mixture 

 of sheep liver and cod-liver oil, while another lot was fed sheep liver alone. The 

 results were in favor of the straight liver diet, the fish thus fed yielding a con- 

 siderably larger percentage of good eggs than those subsisting on the liver and oil 

 mixture. 



The work with the warm-water pondfishes was materially hampered by cold, 

 unseasonable weather during the spring. In an effort to obviate the loss of eggs 

 through the sudden and extreme temperature changes to which this region is 

 peculiarly subject, the adult largemouth bass were transferred from their winter 

 quarters early in March to a pond supplied with a heav}^ flow of water, the idea 

 being to retard the development of their eggs until all danger of extreme temper- 

 ature changes would be at a minimum. This measure proved partially successful, 

 though a severe temperature fluctuation occurring as late as May 27 injuriously 

 affected the results. 



Wythbville (Va.) Station 



[C. B. Grater, Superintendent] 



The spawning season of the rainbow trout began on October 19 and closed 

 February 2, the yield of eggs being 965,000. The quality of the spawn was 

 appreciably impaired as a consecjuence of the very low water supply available 

 for the brood fish during the preceding spring and summer. The condition 

 finally became so acute that it was necessary to transfer them to a series of ponds 

 on a lower level, where more water was available. The effect of this increased 

 flow of water of somewhat higher temperature than customary was to noticeably 

 advance the maturity of the fish and lower the quality of their spawn. On 

 attaining the eyed stage 201,000 of the eggs were shipped on assignment. Less 

 than 38 per cent of the remaining stock hatched, and subsequent losses of fry 

 in proce-ss of rearing reduced the output of fingerling fish to 129,600. Late the 



