FISHES OF THE YELLOWSTONE NATIONAL PARK. 



27 



In streams where overgrowth prevents fly casting, angleworms, 

 grasshoppers, or almost any bait will be taken when the trout is 

 feeding. Everything will be disregarded when it is not feeding. 

 The best flies to use in any body of water must be learned by experi- 

 ence, but the brown hackle is seldom a failure anywhere. Professor, 

 queen of the water, Montreal, coachman, and many others are usu- 

 ally quite successful. Gauze-winged flies will sometimes succeed 

 when others fail. The best time to fish for this trout is in the morning 

 and early evening. It lurks in eddies and pools and at the foot of 

 rapids or under overhanging banks, old stumps., or rocks. 



9. YELLOW PERCH (Perca flavescens). 



The yellow perch has a wide eastern distribution. It is common 

 in the Great Lakes and the tributaries of the upper Mississippi River 



FIG. 9. Yellow perch. 



and in coastwise streams and "lakes from Nova Scotia to North 

 Carolina. 



In 1919 this fish was found by the senior author to abound in 

 Goose and Feather Lakes in the park. Its presence there is appar- 

 ently traceable to an unofficial, unauthorized plant made many years 

 ago by a Montana citizen, who is said to have obtained a consignment 

 of yellow perch from the State of Washington, into which State the 

 species had been introduced some years before. 



In the park lakes the yellow perch attains a length of a foot and is 

 most readily caught by the use of small spinners cast from shore and 

 rapidly drawn in. Only a few of the park authorities have been 

 aware of the occurrence of this fish in local waters. It can not be 

 regarded as a desirable addition to the fish life of the park, and its 

 spread to other waters than those now inhabited should be prevented. 

 It is not usually reputed to be a game fish, and its voracious habits 

 make it a menace to young trout. When fresh from cold water, it is 

 one of the best of pan fishes, being firm-meated and of delicious 

 flavor. 



