THE SALMONS OF THE PACIFIC COAST. 



There are five species of salmou on the Pacitic coast which belong 

 to the genus Oncorhynchus^ namely, the chinook or quinnat salmon 

 {Oncorhynchus fschaivytscha), the red or blueback salmon [Oncorhynchus 

 7icrka], the humpback salmon {Oncorhynchus gorhuscha), the silver 

 salmon {Oncorhynchus kisutch), and the dog salmon {Oncorhynchus Iceta). 

 The features which separate the Pacific salmons from the Atlantic salmon 

 are not marked and consist chiefly in a larger number of rays in tlie 

 anal fin, and more branchiostegals, gillrakers, and pyloric coeca. 



The characters noted in the following key will usually be sufficient to 

 distinguish thedillerent species of Pacific salmon: 



Quinnat salmon: Scales in longitudinal series from 135 to 155, aver- 

 aging about 145; pyloric cceca 110 to 185; gillrakers comj)aratively 

 short and nsually 23 in number, 9 being above the angle; rays in anal 

 fin IG; branchiostegals 15 to 19, Body robust; bead conic; eye small; 

 caudal fin deex^ly forked. Color above dusky, sometimes with bluisb or 

 greenish tinge; sides and belly silvery; head dark, witb metallic luster; 

 back and the dorsal and caudal fins with numerous round black spots. 



Blnebach salmon: Scales in longitudinal series about 130; pyloric 

 c(jeca, 75 to 95; gillrakers comparatively long and 32 to 40 in number; 

 rays in anal fin 14 to 10; branchiostegals 13 to 15. Body rather slen- 

 der; caudal fin much forked; anal and dorsal fins low. Color, above 

 bright blue, sides silvery, no spots. 



Humphaclc salmou : Scales very small, 210 to 240 in longitudinal series; 

 pyloric ('(jeca very slender, about 180 in number; gillrakers short, about 

 28, 13 being above angle; anal rays 15; branchiostegals 11 or 12. 

 Color, bluish above, silvery on sides; hind j)art of back, adipose fin, and 

 tail with numerous black spots, largest and of oblong form on tail. 



Silver salmon : Scales large, 125 to 135 in longitudinal series ; pyloric 

 cu'ca comparatively few and large, 45 to 80 in number; gillrakers long 

 and slender, 23 in number, 13 below angle; anal rays 13 or 14; branchi- 

 ostegals 13 or 14. Body long; head short, conic; snout blunt; eye 

 small; tins small, caudal deeply forked. Color bluish greem, sides sil- 

 very, finely punctulated ; spots few and obscure on head, back, dorsal, 

 adii)Ose dorsal, and upper rays of caudal. 



Dog salmon: Scales of medium size, 138 to 155 in lateral line; pyloric 

 co'ca 140 to 185; gillrakers short and few, 9 above and 15 below angle; 

 13 or 14 rays in anal fin; branchiostegals 13 or 14. Form of quinnat, 

 but head longer and more depressed. Dusky above and on head, paler 

 on sides; very fine spots on back and sides, often wanting; tail i)lain 

 dusky or finely spotted, with black edge; other fins blackish. 



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