50 KEPORT OF THE COMMISSIONER OF FISHERIES. 



portion of the run of adult fish should be allowed to reach the stretches 

 in the lower parts of the streams, where suitable spawning grounds 

 exist. The matter is wholly in the hands of the State authorities 

 and involves the maintenance of adequate fishways over the relatively 

 low dams that cross almost every stream of importance. 



The introduction of the eastern brook trout into Colorado and other 

 Western States has been a conspicuous success. The establishment 

 of brook trout, rainbow trout, lake trout, European brown trout, and 

 Loch Leven trout in selected waters of the Yellowstone National 

 Park has been a noteworthy accomplishment, and similar service in 

 the Glacier National Park is now in progress. 



One of the best, most adaptable, and most widely transplanted of 

 the native trouts is the rainbow, which now affords excellent fishing 

 in practically every State having waters of suitable temperature. 

 As with the eastern brook trout in Colorado and elsewhere, the ac- 

 climatized wild rainbow is now supporting extensive fish-cultural 

 operations in various States. Field stations for the collection of rain- 

 bow trout eggs in Montana and Wyoming have proved veiy pro- 

 ductive. Meadow Creek, a tributary of the Madison River in Mon- 

 tana, operated as an adjunct of the Bozeman station, has yielded 

 nearly 4,000,000 rainbow trout eggs of the best quality during each 

 of the last two seasons. Sage Creek, a tributary of the North Platte 

 River in Wyoming, has afforded the Saratoga station excellent oppor- 

 tunities for taking large numbers of eggs, even with the crude equip- 

 ment that has been available; and the superintendent estimates that 

 with proper appliances this field will yield 10,000,000 eggs annually. 



ARTIFICIAL PROPAGATION OF FRESH-WATER MUSSELS. 



The usual work in mussel propagation was conducted in the field in 

 suitable sections, as heretofore, under the general direction of the 

 fisheries biological station at Fairport, Iowa. A total of 183,021,720 

 glochidia in a condition of parasitism on fishes were liberated in pub- 

 lic waters as compared with 136,907,365 liberate'd last year, an in- 

 crease of 46,114,355. 



Infection of rescued fishes in the vicinity of Minneiska, Minn., on 

 the Mississippi River and at various points as far south as Dakota, 

 Minn., was accomplished in cooperation with the rescue work of one 

 of the fish-cultural crews operating under the direction of the Homer, 

 Minn., station. The number of fishes rescued in connection with the 

 propagation of mussels was 907,995, of which 36,442 were adults. 

 Of the total number of fishes rescued, 22,567 were infected with 

 glochidia before being restored to the rivers. 



Three species of commercial mussels Avere propagated, the leading 

 one being Lampsilis luteola^ commonly Iniown as the Lake Pepin 

 mucket. The infected fish hosts were liberated in the Mississippi 

 River off Fairport, Iowa ; in Lake Keokuk, Iowa, and 111. ; in 

 the Mississippi River at New Boston and Oquawka, 111. ; in the Mis- 

 sissippi River at Lake Pepin, Minn, and Wis. ; at various points along 

 the Missivssippi River, between Minneiska and Dakota, Mimi. ; in 

 Lake Pokegama, Minn.; and in the Wliite River in the vicinity of 

 NeAvport, Ark. 



Small numbers of mussels reared at the Fairport station were 

 planted in public waters at the following places : Lake Keokuk, Iowa 



