2818 Bulletin ^7, United States National Museum. 



Page 492 : 



779. SALMO MYKISS, Walbaum. 



(MYKISS; SOMKA; KAMCHATKA SALMON TROUT.) 



By an unfortunate error the writers have heretofore used the name 

 Salmo mykiss for the Cutthroat Trout of the Northwest. It was known 

 that the Cutthroat is the only true or black-spotted trout in Alaska, and 

 it was assumed that its range extended along the coast to all streams in 

 Bering Sea. But our recent explorations have shown that it probably 

 does not occur in Bering Sea, nor is there any undoubted record to the 

 north of Wraugell. If it reaches Kadiak or Sitka or Prince William 

 Sound, it is only rarely, and the streams of the Aleutian Islands and the 

 east coast of Bering Sea contain no species of Salmo. The name Salmo 

 mykiss must, therefore, be restricted to the Kauichatkan species, while the 

 species of the American rivers heretofore called Salmo mykiss must stand 

 as Salmo clarkii. We have, therefore, studied with great interest a speci- 

 men of the genuine Salmo mykiss, the first on record since the times of Pal- 

 las, Krasheninnikof, and Steller. The specimen, an adult male, 960 mm. 

 long, was taken by Dr. Leonhard Stejneger, September 15, 1897, in the Ka- 

 lakhtyrka River, near Petropaulski, Kamchatka. It was called "Souka" 

 or "Somka" by the natives. It is said to occur rarely and to be found in 

 but few rivers, the Kalakhtyrka among them. It is considered to be 

 superior as food to other Salmonidas, except the King Salmon (O. tschaw- 

 ytscha). Head 4 in length; depth 4. D. 11. A. 10 (developed rays); 

 scales 125-24. Mouth large, the maxillary 1* in head, being somewhat 

 produced at tip; vomerine teeth few, evidently deciduous, only 3 being 

 present. Eye 8|- in head; snout 2f. Pectoral 2 in head, longest anal ray 

 2f. Anal fin high and somewhat falcate; ventrals inserted under ante- 

 rior third of dorsal, reaching about halfway to vent; adipose fin over 

 posterior end of anal; caudal lunate. Color dark grayish above, sides 

 silvery; a few small, faint, round black spots on back and on top of head, 

 these sparse and obscure, 1 a few faint spots on base of dorsal, and some on 

 adipose dorsal; spots on caudal small, but distinct, especially in middle 

 of fin; no trace of red at throat, in example preserved in formalin, and 

 doubtless none in life. The specimen is now a half skin, in good condition . 



The following measurements were taken from the fresh specimen by 



Dr. Stejneger: 



Millimeters. 



Total length 960 



Totallength without caudal 853 



Head 215 



Tip of nose to anterior end of dorsal 400 



Length of base of dorsal 1 00 



Posterior end of dorsal to anterior end of adipose fin 167 



Length of base of adipose fin 17 



Posterior end of adipose to caudal '81 



Posterior end of anal to caudal .1 81 



Length of base of anal 71 



Anterior end of anal to posterior end of ventral 165 



Height of body in front of dorsal 195 



Height of body at posterior end of adipose and anal fins 105 



