12 



The flsh known commercially as Pacific Salmon are zoologically 

 difeerent from the Atlantic Salmon, the former belonging to the genus 

 Oncorhynchus while the latter is a species of Salmo. The technical 

 differences between these two genera are rather finely drawn, but the 

 crucial point is in the count of the rays in the anal fin. In Salmo 

 the number ranges from 9 to 12, while in Oncorhynchus there are 

 from 14 to 20. Five species of Pacific Salmon exist in our waters. 



The Chinook Salmon, Oncorhynchus tschawytscha (Walbaum), 

 (Pig. 15) is the noblest of the salmon tribe since it outranks all other 

 species in size and quality. Specimens are on record weighing more 

 than 100 pounds. In different parts of its range it has -been given 

 a number of common names such as Tyee, King, Quinnat, Spring, etc. 

 The technical points that mark this species from its relatives are as 

 follows. The gillrakers number from 20 to 25. The scales are of 

 medium size, 135 to 155 in longitudinal series. The branchiostegal 

 rays number from 15 to 19. The back and upper fins are marked with 

 round black spots. 



The Sockeye, Oncorhynchus nerka (Walbaum), (Fig. 17) is known 

 in other parts of its range as Blueback and Red Salmon. It is of 

 immense economic importance because it constitutes the main run of 

 salmon in the rivers of Alaska and British Columbia. It is discrim- 

 inated by the following combination of characters. The gillrakers are 

 numerous, ranging from 30 to 40. The scales are large. The count 

 of scales on the lateral line is about 130, while the number of branch- 

 iostegal rays is from 13 to 15. The color is clear blue above and 

 silvery on the sides. In the adult there is no black spotting, but in 

 the young fish obscure markings are present. During the breeding 

 period the color changes, more or less dark red appearing on the back 

 and sides. The Sockeye attains a length of two feet and a weight of 

 from 3 to 7 pounds. It does not run in rivers that are unconnected 

 with lakes. 



The Silver Salmon or Coho, Oncorhynchus kisatch (Walbaum), 

 (Fig. 16) stands third in commercial importance among the Salmon. 

 It attains a length of 15 inches and a weight of from 3 to S pounds. 

 It is particularly abundant in Puget Sound and is particularly valu- 

 able as a fresh product. The Silver can be recognized by its peculiar 

 bluish green back and silvery sides. Spots are absent except a few 

 obscure markings on the upper portions of the body. The scales are 

 relatively large, with 125 to 135 in longitudinal series. The anal fin 

 has 13 or 14 rays while the branchiostegals number the same. 



The Humpback or Pink Salmon, Oncorhynchus gorbuscha (Wal- 

 baum), (Pig. 18) is the smallest species in the genus, attaining a 

 weight of 3 to 6 pounds. It is regarded as of inferior merit as a 

 canned product but considerable quantities of it are put up for the 

 market. It may be distinguished by the scales, which are very small. 



