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Know the Difference: Salmon and Brown Trout

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Attention Anglers:

Know the Difference Between Salmon and Brown Trout

Migratory and landlocked Atlantic salmon juveniles and adults can be difficult to distinguish from brown trout. There are size and bag limit restrictions that differ for these two species; therefore, it is important to know how to identify them properly.


Young Salmon & Brown Trout

Here’s what you need to know:

Set young salmon free! Study these pictures and note the points of difference between young salmon and brown trout. If you catch a salmon parr or smolt, remove the hook gently and place the fish back in the water to grow up.

Atlantic Salmon Parr

Similar markings to a brown trout.

Salmon Parr F.psd

  • Jawline extends to midpoint of eye
  • No Spots on dorsal fin
  • Adipose fin not tinged with red (greyish)
  • Very forked tail


Brown Trout Parr

A colorful fish with red and black dots along its sides and very similar in appearance to salmon parr.

Salmon Parr F.psd

  • Jawline extends to posterior of eye
  • Spots usually evident on dorsal fin
  • Adipose fin tinged with red
  • Tail more rounded, less forked


Salmon Smolt

Almost totally silver. Generally lacks the vertical sidebars of the salmon parr or brown trout.

Smolt F.psd

  • Jaw extends to midpoint of eye
  • Black spots on upper sides and cheeks
  • Vey Forked tail.



Adult Salmon & Brown Trout

Here’s what you need to know:

The more obvious differences between adult salmon and brown trout may be found in the head and tail areas. Knowing them may help the angler release a fish more quickly. When in doubt about identifying adult salmon and brown trout, play it safe and release the fish unharmed.


Atlantic Salmon F.psd SalmonMouth.tif
  • Caudal fin may be slightly forked
  • Caudal peduncle is narrow and tapered
  • dipose fin is grey to olive—never orange
  • Maxillary usually extends to rear edge of eye or slightly beyond
  • Vomerine teeth

    Small and arranged in a single row along a raised shaft on the roof of the mouth.

Brown Trout F.psd BrnTroutMouth.tif
  • Caudal fin is square and unforked
  • Caudal peduncle is thick and stocky
  • Adipose fin may be fringed or spotted with orange or red
  • Maxillary usually extends well past rear edge of eye
  • Vomerine teeth

    Well developed and arranged in zig-zag rows along a raised shaft on the roof of the mouth.

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