386 U. S. BUREAU OF FISHERIES 



yearling rainbow in September 1933. Only 24 reports were received 

 from anglers for the month of May, and these reported 82 rainbows 

 of the 1933 planting. Three reports were received later, which 

 brought the total number of rainbows caught during the season to 

 87 fish. This is a return of approximately 12 percent. Since it was 

 evident that only a small percentage of the anglers reported their 

 catch, it is believed that the returns from this planting were quite 

 satisfactory. One rainbow was reported which had been planted in 

 1932. These experiments are being repeated during the present 

 season. 



In cooperation with the Middlebury College an attempt was made 

 to obtain similar data on waters stocked and controlled by the col- 

 lege. Special permits required of those fishing in streams on college 

 property were issued with the understanding that each angler would 

 report his daily catch in a space reserved for this purpose on the 

 permit. Even under these circumstances it was found very difficult 

 to get returns, and the reports received were too meager to throw 

 much light on trout-stream production. They do show, however, 

 that the average daily catch of legal-size fish was 9.4 per trip in 

 1933 and 7.4 per trip in 1934. The reports also show that the num- 

 ber of short trout taken and returned to the stream greatly exceed 

 the number of those which had reached le^al size. 



California trout investigations. — Work has progressed rapidly on 

 most of the projects initiated in 1932 when these investigations were 

 started. Subsequent experience necessitated several modifications of 

 the original program and the work now consists of two major proj- 

 ects, the Hot Creek brood stock experiment and the coastal stream 

 steelhead studies. The former project is under the direction of Dr. 

 P. R. Needham, who is also in charge of the field program as a whole. 

 The latter project is under the supervision of A. C. Taft. Work on 

 several minor projects is being carried on as time permits. Three 

 assistants are supplied to the work by the California Division of 

 Fish and Game. 



The Hot Creek experimental project was greatly expanded this 

 year with the construction of a series of 12 concrete raceways, 20 feet 

 long by 4 feet wide. Two new ponds to hold brood stock were also 

 constructed as well as a combination garage, meat house, and labora- 

 tory. Late in the fall a small experimental hatchery was completed 

 with C. C. C. labor. Over $3,000 Avas expended on these improve- 

 ments. Over 67,000 small trout, consisting of 6 separate strains of 

 rainbows and 1 lot of eastern brook trout, were placed in the ponds 

 after construction work was completed. These fish are to form 

 nuclei for rearing select domestic brood stocks for experimental pur- 

 poses. An additional source of rainbow eggs is needed in California, 

 and breeding experiments for high egg yields, rapid growth, colora- 

 tion, and other genetically desirable characteristics, therefore, will be 

 carried on largely with this species. One distinct advantage offered 

 at the Hot Creek area is the tremendous natural production of 

 shrimp, making it unnecessary to feed artificial food to many of tha 

 younger fish, thus reducing costs materially. Over a quarter of a 

 poimd of pure shrimp were taken from an area of 1 square foot in 

 the watercress in one of the ponds. A fine series of springs supply 

 about 3*0 serond-feet of water at temperatures varying from 57° F. 

 to 68° F. which permit rapid growth over most of the year. 



