Family SALMONIDAE 



THE SALMON AND TROUT FAMILY 



The family Salmonidae includes the salmon and the trout and consti- 

 tutes one of the most popular families of game and food fishes. These are 

 long-bodied fishes with naked heads. They are characterized by rela- 

 tively small cycloid scales and a well-developed adipose fin. The anal fin 

 has from 9 to 16 rays. The dorsal fin is single and has from 10 to 12 rays; 

 no spines are present. The ventral fins are located just below the dorsal. 

 A slit is present behind the fourth gill; the pseudobranchiae are devel- 

 oped; the gill-membranes are not joined to the isthmus; the branchioste- 

 gal rays number 10-20. The air bladder is large. Many pyloric caeca are 

 present. 



These fishes are closely allied to the family Coregonidae but differ in 

 the possession of stout gill-rakers and strong teeth lining the jaws, 

 palatines, and margin of the tongue. The scales in the lateral line number 

 more than 100. The fishes of this family are cold-water fishes, circum- 

 polar in distribution. During the breeding season the males commonly 

 develop secondary sexual characters, consisting usually of hooked jaws 

 and sometimes, as in the salmon, of fleshy humps. Most of the members 

 of this family lay their eggs in the fall, but the eggs do not hatch until 

 early spring. The eggs can easily be kept alive on ice. and they have 

 been shipped to many parts of the world. 



Key to Common Species of Family SALMONIDAE 



L Tail deeply forked; no bright colors; body gray with light spots 



. . . .Common Lake Trout, Cristivomer namaycush namayctish (Walbaum) 

 Tail square or slightly forked; brown spots and frequently red or orange 

 spots 2 



2. Lateral line scales more than 200; light wormlike streaks on back; anal and 



paired fins with white margins 



Common Brook Trout, Salvelinus fontinalis jontinalis (Mitchill) 



Lateral line scales less than 200; no wormlike streaks on back 3 



3. Rather large and diffuse dark spots, few on caudal; red spots ocellated with 

 blue sometimes present on body . . .Brown Trout, Salmo trutta fario Linnaeus 

 Rather small and distinct dark spots, profuse on caudal; red sp>ots absent; 



longitudinal crimson streak on body varying in intensity 



Coast Rainbow Trout, Salmo gairdnerii irideus Gibbons 



GENUS Salnw Linnaeus 



Members of this genus include the Atlantic salmon and many of the 

 native trout. They are distinguished bj'- a flat vomer bearing one or two 

 rows of teeth on the shaft and by relatively large scales numbering not 

 over 200. 



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