Chinook Salmon
  • Side view adult.
  • Side view adult.
  • Side view adult.
  • Top view adult.
  • Bottom view adult.
  • Head-on view adult.
  • Close-up flank.
  • Close-up head.
  • Close-up mouth and snout.
  • Close-up tail.
  • Close-up dorsal fin.
  • Close-up anal fin.
  • Close-up pectoral fin.
  • Close-up pelvic fin.
  • There are 10-14 principal dorsal rays; the dorsal fin also shows spots.
  • Close-up of tail region of a young-of-year: The adipose fin is not edged in red.
  • There are spots on the tail, which are much more pronounced in spawners.
  • The flanks show small dark spots on light background, no red spots, and 130-135 lateral line scales.
  • The head region shows dark spots on light background being much smaller than the pupil.
  • There are 14-19 principal anal rays; there are no spots on the anal fin of this specimen, but they are numerous in spawners.
  • Close-up gill rakers: There are 16-26 gill rakers.
  • There are 140-185 pyloric caecae.
  • Inside of the mouth: Notice that the vomerine teeth on the middle of the roof of the mouth are well-developed .
  • The inside of mouth of this breeder is completely black.
  • View of underside of lower jaw: There are usually 13-19 branchiostegal rays on each side. The jaw of this specimen has a hook wound.
  • This females specimen developed a dark blue-black color.
  • Close-up of pelvic fin: The pelvic fin shows a pronounced axillary process.
  • Close-up of anal fin: There are 14-19 principal anal rays and the anal fin is heavily spotted on a dark background.
  • Close-up head of male and female breeders: Males (top) develop a hooked jaw, females (bottom) do not.
  • Side view of a breeding male: Males develop a dark bluish-purple color.
  • This females specimen developed a dark bluish-purple color.
  • Side view of a breeding specimen held by John Lyons.
  • Side view of a breeding female: Notice the golden-bronze, bluish color.
  • Side view of a breeding male: Male breeders develop a golden colored, hooked lower jaw.
  • Close-up of tails of male and female breeders: The tails are heavily spotted and develop a concave shape (no fork).
  • Close-up of tail region of a young-of-year: They have 14-19 principal anal rays with the 1st rays being only slightly elongated, the fin is only slightly falcate.
  • Close-up of tail region of a young-of-year: They have 14-19 principal anal rays with the 1st rays being only slightly elongated, the fin is only slightly falcate.
  • Side view of a young-of-year: Notice the parr marks.
  • Young-of-year develop parr marks.
  • Alternative side view.
DescriptionSimilar Species
Family
Trouts (Salmonidae)
Body
Mouth and snout: Terminal, large and slightly oblique, with numerous small to medium-sized teeth on the upper and lower jaws. No barbels. Body patterning, color, and scales: SPOTS on side; juveniles also with thick dark vertical bars (“parr marks”). Background body color silvery, silver-blue, or light olive, grading to cream on belly. Spots dark brown or black; round or irregular in shape, substantially smaller than the pupil of the eye. 130-165 cycloid lateral line scales. Dorsal and tail fins tan or olive; both often spotted throughout. Pectoral, pelvic, and anal fins dark gray; anal sometimes spotted. Adipose fin not edged in red or orange. Body shape and size: Body fusiform; oval in cross section. In Great Lakes, typically 450-700 mm (18-28 in) TL; maximum about 800 mm (32 in).
Fins
Tail, dorsal and other fins: Slightly forked to square tail. Single dorsal fin with no spines and 10-14 principal rays. Pelvic fins abdominal with axillary process. Adipose fin present. Anal fin with 14-19 principal rays.
Distinguishing Characteristics
The Chinook salmon can be most easily distinguished by its pattern of dark spots on a light background. See also similar species information.
Breeding Adults
Males develop a hooked upper jaw. The body and fins of both sexes become darker (bronze, brown, or dark gray) with pronounced spots prior to spawning and turn black after spawning.
Juveniles
Have 6-12 oval vertical bars (“parr marks”) on sides. Spots relatively scarce and inconspicuous in young-of-year fish. Older juveniles have more adult-like spotting patterns but retain parr marks, which disappear as the fish smolt and leave the natal stream and move into the Great Lakes.
Hybrids
Chinook salmon X pink salmon, 1 report from Wisconsin (no photo).
Compare Similar Species
Spot Characteristics
Salmon, AtlanticUsually few, covering upper sides; black & sometimes red present; nearly as large as pupil of eye; round, irregular ovals, or “X” shaped
Salmon, ChinookModerate to numerous, limited to upper half of sides; black only; much smaller than pupil of eye; round or irregular in shape
Salmon, CohoUsually few, and limited to back and upper sides; black only; much smaller than pupil of eye; round or irregular in shape
Salmon, KokaneeAlmost none, limited to upper back; black only; much smaller than pupil of eye; round to slightly oval in shape
Salmon, PinkNumerous and on both lobes, forming lines of elongated oval spots along rays
Trout, BrookModerate to numerous; covering sides; cream, light, olive, yellow, red, sometimes with bluish halo; much smaller than pupil of eye; round
Trout, BrownFew to many, covering most of sides; both black and red present; nearly as large as pupil of eye; round or irregular ovals in shape
Trout, LakeMany; covering sides; cream to light olive; much smaller than pupil of eye; irregular shape, much smaller than pupil of eye
Trout, RainbowMany, covering most of sides; black only; much smaller than pupil of eye; round or irregular in shape
Tail Spots
Salmon, AtlanticFew or none, usually limited to base of tail
Salmon, ChinookModerate to numerous and on both lobes
Salmon, CohoFew, limited to top of upper lobe
Salmon, KokaneeNone
Salmon, PinkNumerous and on both lobes, forming lines of elongated oval spots along rays
Trout, BrookFew and lighter
Trout, BrownFew or none, usually limited to base of tail
Trout, LakeNumerous and on both lobes
Trout, RainbowNumerous and on both lobes
Principal Anal Rays
Salmon, Atlantic7-12, usually 9-11
Salmon, Chinook14-19
Salmon, Coho12-17, 1st ray elongated; fin distinctly falcate in YOY
Salmon, Kokanee11-16, usually 13-14
Salmon, Pink13-19
Trout, Brook7-13, usually 9
Trout, Brown8-12, usually 9-11
Trout, Lake8-10
Trout, Rainbow8-12
Lateral Line Scales
Salmon, Atlantic109-121
Salmon, Chinook130-165
Salmon, Coho112-148
Salmon, Kokanee121-140
Salmon, Pink147-205
Trout, Brook210-244
Trout, Brown120-130
Trout, Lake185-210
Trout, Rainbow100-150
Inside of Mouth in Breeders
Salmon, AtlanticWhite
Salmon, ChinookBlack or dark gray
Salmon, CohoBlack or gray; gums white
Salmon, KokaneeDark gray with white mottling
Salmon, PinkTongue and tip of jaw black or gray; gums white
Trout, BrookWhite on the teeth, tongue, and inside of mouth, but black on the gums
Trout, BrownWhite
Trout, LakeWhite
Trout, RainbowWhite
Other Features
Salmon, AtlanticBranchiostegal rays usually 11-12, principal dorsal rays 11-12, adipose fin not edged in red, pyloric caecae 40-74, gill rakers 15-20, vomerine teeth poorly developed, dorsal fin with few or no spots
Salmon, ChinookBranchiostegal rays usually 13-19, principal dorsal rays 10-14, adipose fin not edged in red, pyloric caecae 140-185, gill rakers 16-26, vomerine teeth well developed, dorsal fin spotted
Salmon, CohoBranchiostegal rays usually 11-15, principal dorsal rays 9-12, adipose fin not edged in red, pyloric caecae 45-114, gill rakers 18-25, vomerine teeth well developed, dorsal fin with few or no spots
Salmon, KokaneeBranchiostegal rays usually 13-14, principal dorsal rays 11-13, adipose fin not edged in red, pyloric caecae 50-87, gill rakers 29-43, vomerine teeth well developed, dorsal fin with few or no spots
Salmon, PinkBranchiostegal rays usually 9-15, principal dorsal rays 10-15, adipose fin not edged in red, pyloric caecae 95-224, gill rakers 24-35, vomerine teeth well developed, dorsal fin with few or no spots
Trout, BrookBranchiostegal rays usually 9-13, principal dorsal rays 10-14; adipose fin not edged in red, but dark margin in young; pyloric caecae 23-55; gill rakers 9-12; vomerine teeth well developed; dorsal fin spotted
Trout, BrownBranchiostegal rays usually 10, principal dorsal rays 9-11, adipose fin often edged in red, pyloric caecae 30-60, gill rakers 14-17, vomerine teeth well developed, dorsal fin spotted
Trout, LakeBranchiostegal rays usually 10-14, principal dorsal rays 8-10, adipose fin not edged in red, pyloric caecae 93-208, gill rakers 16-26, vomerine teeth well developed, dorsal fin spotted
Trout, RainbowBranchiostegal rays usually 9-13, principal dorsal rays 10-12, adipose fin not edged in red, pyloric caecae 27-80, gill rakers 16-22, vomerine teeth well developed, dorsal fin heavily spotted
Similarity Index
Salmon, AtlanticVery similar
Salmon, ChinookN/A
Salmon, CohoVery similar
Salmon, KokaneeVery similar
Salmon, PinkVery similar
Trout, BrookModerately similar
Trout, BrownVery similar
Trout, LakeModerately similar
Trout, RainbowVery similar
Comments
Salmon, AtlanticNot native; stocked in the past without estabishing a population. Occurs only in the Great Lakes as a rare stray from other states and Ontario.
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