Key to the Species of the Family Salmonidae

1. Scales small, those in lateral line 115-200; teeth well developed on jaws and vomer; caudal usually truncate, occassionally forked; young (6 inches or less) with dark vetical blotches (parr marks) on sides (except O. gorbuscha)

Salmons, trouts, chars(Salmoninae).......................................2

Scales large, those in lateral line 100 or less; teeth weakly developed of absent; caudal fins distinctly forked; parr marks usually absent (except Prosopium and Thymallus); colour generally silvery, silvery green, or blue.

Whitefishes (Coregoninae) and grayling (Thymallinae).......14

2. Anal rays 13-19 (usually 14-16); body and caudal fin of adults with black spots. Pacific salmons, (Oncorhynchusspp.)................................10

Anal rays 7-12 (usually 9-11); body and caudal fin with or without black spots....................................................................................................3

3. Black spots present on head and body(young S. salar have red spots between parr marks); scales conspicuous, fewer than 165 in lateral line; pelvic and anal fins without white leading edges; vomer flat with teeth extended backward in 2 rows.........................................................4

Light spots, not black spots, on body, these spots being pink, red, or cream colour; scales not conspicuous; lower fins with snow-white leading edges; vomer boat shaped, teeth on the anterior part only…………………………….......………………..7

4. Caudal fin distinctly marked with radiating rows of black spots; body never with red spots; adipose often with black margin; scale rows 120-180…………............................…...............................5

Caudal fin usually unspotted; but never with regular rows of black spots; reddish spots sometimes on body; scale rows usually 110-130…………...............................................................6

5. Red or orange-red dash on lower jaw, along inner border of mandible; minute teeth usually present at base of tongue (basibranchial teeth).

Cutthroat trout, Onchorynchus clarki

No red coloration present on lower jaw; minute teeth at base of tongue absent.

Rainbow trout, Oncorhynchus mykiss ¹

6. Maxillary to below centre of eye in 6-inch fish, seldom far behind eye (except in large males); gill cover with 2 or 3 large spots only; branchiostegals usually 12; dorsal fin rays usually 11; vomerine teeth usually not well developed; small fish have red spots between parr marks; no red on adipose fin.

Atlantic salmon, Salmo salar

Maxillary to below last half of eye on 5-inch fish, and extending well beyond eye in larger fish; gill cover usually with many spots; branchiostegals usually 10; dorsal fin rays usually 9; vomerine teeth well developed; rust-red spots sometimes on adults and ofter on margin of adipose fin.

Brown trout, Salmo trutta

7. Caudal fin deeply forked; dorsal and caudal fins, body and head covered with small, often bean-shaped light spots, body never brightly coloured with orange or red; parr marks quite irregular, and narrow; pyloric caecae over 90.

Lake trout, Salvelinus namaycush

Caudal fin square (truncate) or slightly forked, body with light-coloured spots of cream, pink, or red; dorsal and caudal fins with dark wavy lines and marks, or unspotted, without light spots;pyloric caecae less than 75………………………………………………….8

8. Caudal fin square or nearly so; dorsal and caudal fins with distinct, dark wavy lines or blotches; lower fins with pure white leading edges usually followed by black; back usually with wavy lines(vermiculations); sides with pink or red spots, many of which have blue borders; young with 8-10 regularly arranged parr marks on sides.

Brook trout, Salvelinus fontinalis

Caudal fin nearly square or slightly forked, (may be deeply forked in freshwater populations in eastern Canada) without dark wavy lines on dorsal and caudal fins; lower fins with pure white leading edges, but not usually followed by black; sides with creamy, pink, or reddish spots, not extending onto fins; parr marks vague or irregular, not well defined……………………......................................9

9. Spots usually large and less numerous; gill rakers on upper limb of first gill arch 7-13, on lower limb 12-19; pyloric caecae 20-74.

Arctic char, Salvelinus alpinus

Spots round, small, and numerous; gill rakers on upper limb of first gill arch 3-9, on lower limb 8-14; pyloric caecae 13-47.

Dolly varden, Salvelinus malma

10. Distinct black spots on back and on caudal fin…...................................................................11

No distinct black spots on back or caudal fin but fine black speckling may be present.………………….................……13

11. Large black spots on back and caudal fin, the largest as large as eye; scales small, 169-229 in first row above lateral line; gill rakers 26-34.

Pink salmon, Oncorhynchus gorbuscha

Spots on back and caudal fin small, largest as large as pupil of eye; scales moderate, fewer than 154 in first row above lateral line; gill rakers 19-28……………….......................................…….12

12. Small black spots on both lobes of caudal fin; flesh at base of teeth of lower jaw black; pyloric caeae 140-185; gill rakers 20-28.

Chinook salmon, Onhorhynchus tshawytscha

Small black spots when present on tail on upper lobe only; flesh at base of teeth of lower jaw pale; pyloric caecae 45-80; gill rakers 19-25

Coho salmon, Oncorhynchus kisutch

13. Gill rakers on first arch 30-40, long, slender and crowded; prloric caecae 60-115.

Sockeye salmon (or kokanee), Oncorhynchus nerka

Gill rakers on first arch 30-40, short, stout and widley spaced; pyloric caecae 140-186.

Chum salmon, Oncorhynchus keta

14. Dorsal fin base equal to or longer than head, dorsal fin usually with more than 17 rays, fin large and sail-like on fishes 8-inches or larger; colour of back blueish purple, dorsal and pelvic fins sometimes with green or reddish spots.

Arctic grayling, Thymallus arcticus

Dorsal fin base shorter than head, dorsla fin rays fewer than 17; dorsal fin not expanded; colour usually silvery, back sometimes black, blue, or green.

Whitefishes (Coregoninae)

¹ Formerly known as Salmo gairdneri

This key was taken from: Crossman, E.J. and W.B. Scott 1969. Checklist of Canadian freshwater Fishes with Keys for Identification. Life Sci. Misc. Publ., R. Ont. Mus. pp.36-39.