PROPAGATION AND DISTRIBUTION OF FOOD FISHES, 1925 485 



bridges, retaining walls, and water-supply pipes, and covering the reservation 

 with water to a depth of several feet. The large stock of brood rainbow trout, 

 smallmouth black bass, and rock bass on hand in the station ponds was released 

 by the flood waters into Spring Branch, though a considerable number of the 

 fish were recovered later with seines and will Vie used as the basis for a new brood 

 stock. In the hatchery, where fingerling brook and rainbow trout aggregating 

 627,000 were being held in troughs awaiting distribution, the entire stock was 

 swept away, all, with the exception of the few lost on the grounds when the 

 waters receded, being carried into the Macjuoketa River and Spring Branch. 



During the previous winter rainbow-trout eggs of fine quality were obtained 

 from the station brood stock between December 9 and March 26, the total 

 amounting to 1,076,000, or nearly twice the number collected the preceding year. 

 On reaching the eyed stage 690,000 were shipped to applicants in five States. 

 The remaining eggs were incubated in the hatchery, and the resulting fry were 

 carried away during the flood, together with the product of 25,000 eggs from wild 

 rainbow trout received in May from the Meadow Creek (Mont.) field. 



Eight hundred and twenty thousand eyed brook-trout eggs were received from 

 commercial dealers in exchange for eggs of other species, and 500,000 were 

 transferred from the Leadville (Colo.) field. The fry resulting from the latter 

 were among the fish carried away by the flood, but the majority of those hatched 

 from the commercial eggs had l^een distributed previous to its occurrence. The 

 year's output also included limited numbers of fingerling smallmouth bass and 

 rock bass, the product of the spring spawning of the previous year. Hope had 

 been entertained that a good showing might be made in the production of pond- 

 fishes in the spring of 1925, but all efforts along that line were nullified by the 

 storm. All brood smallmouth bass and rock bass, together with an unknown 

 number of fry, were released, the results of the spring work proving a complete 

 failure. In the course of the j^ear a considerable amount of improvement work 

 on the hatchery and other buildings was accomplished, all of it being done by 

 the station force. 



Neosho (Mo.) Station 



[F. J. Foster, Superintendent] 



The j^ear at this station was one of the most successful in its history. As in 

 former years, fish-cultural activities were confined mainly to the propagation of 

 rainbow trout and largemouth black bass, though considerable numbers of fish 

 of other species were incidentally produced. In the course of the rainbow-trout 

 spawning season (from November 1 to February 28) 1,357,160 eggs were col- 

 lected, of which 696,000 in the eyed stage were consigned to applicants and other 

 stations of the bureau. An outstanding feature of the work with this species was 

 the material increase over past years in the number of large fingerUngs produced, 

 approximately two-thirds of the fingerlings distributed being in the No. 4 stage or 

 larger. It is believed that the present policy of discarding practically all brood 

 trout after their first spawning season is at least partially responsible for the 

 marked improvement in the quality and quantity of the spawn collected, the 

 comparatively large size of the fish distributed, and the low average cost of egg 

 production, the latter item, based on the food consumed by the parent stock, 

 amounting to 23^/^ cents per thousand, a reduction of 53^ cents as compared 

 with its cost in the preceding year. 



Though the health of the adult and yearling trout was generally satisfactory 

 throughout the year, a constant and vigilant watch had to be maintained to 

 prevent heavy losses of fingerling fish from the ravages of parasitic enemies. 

 Monthly and often bimonthly treatments with vinegar solution were applied 

 for the removal of gyrodactylus, and one trough of fry, still in the sac stage, 

 became heavily infested with ichthyophthirius. As the fish at that time were 

 still at the bottom of the trough, remedial measures were difficult to apply and 

 fully half of this lot succumbed before the parasite could be eliminated. 



The greatest loss experienced at this station continues to be from the affection 

 known as crystals in the kidneys, which makes its appearance in fingerling fish 

 from IH to 23^ inches long. There is ground for the hope that this trouble may be 

 overcome, one reason being that the Ijrood fish resulting from eggs shipped from 

 the Madison Valley (Mont.) field two years ago have never been seriously affected 

 by it; another is that the lot of fish experimentally fed on yeast and cod-liver oil 

 continued in good health to the end of the season. Apparently the disorder is 

 local as it has never been known to develop in fingerlings hatched from eggs 

 shipped by the station to other points. 



