20 U. S. BUREAU OF FISHERIES. 



The size attained by trout in the park waters, as elsewhere, varies 

 much with locality and conditions. Fish of over 4 pounds have been 

 reported. 



This trout in some waters is a highly esteemed game fish and can 

 be taken in all sorts of ways spoon, phantom, natural bait, artificial 

 fly, etc. Mary Trowbridge Townsend (1. c.) writes of it in the Fire- 

 hole River: 



The father of the Pacific trout, the blackspotted ' ' cutthroat " with the scarlet splotch 

 on his lower jaw, was most in evidence, with long symmetrical body, graduated black 

 spots on his burnished sides. He is a brave, dashing fighter, often leaping salmon-like 

 many times from the water before he can be brought to creel. We found him feeding 

 on the open riffs or rising on the clear surface of some sunlit pool. 



Ralph E. Clark wrote (1. c.) that "the dark, silvergray trout of 

 the West seem to favor flies more in harmony with their own color- 

 ing," and mentioned the gray hackle, brown hackle, coachman, 

 grizzly king, Seth Green, black gnat, and white moth : 



The junction of Yellowstone and Lamar Rivers is noted for fine fishing. If you find 

 the waters high, swift, and roily, you will probably try your flies in vain. Put on a 

 spinner or a little spoon and watch the fish rise to it, almost touch it, and then go 

 away. They are after live bait and won't touch anything else. The grasshoppers are 

 abundant. Catch a few, bait your hook carefully, and let it float down with the 

 current. A large trout will rise to it, and if you are not very careful he will steal it 

 from you. 



This is an excellent food fish when fresh from cool waters, but the 

 trout from some parts of the Yellowstone Lake, Upper Yellowstone 

 River, and Heart Lake are generally reputed to be infested with a 

 parasitic worm. In his book previously cited in the list of publica- 

 tions pertaining to the fish of the park, Gen. Chittenden says : 



The trout of Yellowstone Lake are to a slight degree infected with a parasitic 

 disease that renders them unfit for eating. Many efforts have been made to discover 

 the cause of this condition and a suitable remedy for it, but so far without success. 

 An explanation sometimes advanced is that the excessive number of these fish and the 

 absence of sufficient food reduce the vitality and they become an easy prey to para- 

 sites which a more vigorous constitution would throw off. Later investigations have 

 shown that reports of the prevalence of this condition were much exaggerated. 



The parasite referred to is a tapeworm, of which only the larval or 

 intermediate form occurs in the trout, the host of the adult being 

 an entirely different animal, as is the case with all tapeworms of this 

 kind. Briefly, its life cycle has been found to be as follows : Starting 

 with the egg in the water, it develops into a ciliated embryo. This 

 passes into the fish, probably by way of the mouth, and becomes 

 established and assumes the form usually observed. The fish is 

 eaten by the pelican, and in the intestinal tract of that bird the 

 parasite attains its adult and reproductive stage, and its round of 

 life is there completed. The eggs pass into the water and a new 

 generation is begun. 



Gen. Chittenden's statement that the parasite renders the fish 

 unfit for food involves a matter of prejudice rather than actual unfit- 

 ness for food or danger to the consumer. Cooking destroys the 

 vitality of the worm, and it may be said that this particular worm is 

 not harmful to man. Probably no one would knowingly eat an in- 

 fected fish, but if he should there would be absolutely no danger in 

 doing so. Beyond doubt the presence of this parasite is greatly 

 exaggerated, as Gen. Chittenden says, and lean, cadaverous, un- 



