How to Identify Lake Trout

To identify Lake Trout (Salvelinus namaycush), look at these key features.

Physical Characteristics

Body shape

torpedo

Coloration

Typically dark green to grey or brown on the back, fading to lighter sides and a white belly. Distinctive pale, irregular spots (cream to yellowish) cover the head, body, and fins, including the dorsal and caudal fins. The intensity and size of spots can vary geographically and with morphs. Spawning males may develop a reddish or orange hue on their lower flanks.

Scale type

cycloid

Mouth position

terminal

Distinctive features

Deeply forked caudal fin (tail fin), Presence of an adipose fin (small, fleshy fin between dorsal and caudal fins), Pale, irregular spots on a darker background, extending onto fins, Large mouth extending beyond the posterior margin of the eye, Absence of teeth on the shaft of the vomer (a bone in the roof of the mouth), distinguishing it from true trout (Oncorhynchus and Salmo)

Dorsal fin

Single, relatively short dorsal fin, typically with 10-14 rays. Followed by a small, fleshy adipose fin.

Tail fin

Deeply forked, a key distinguishing feature among chars.

Pectoral fin

Paired, moderately sized, located low on the body.

Distinctive fins

Pelvic fins are also paired and located abdominally. All fins, except the adipose, typically have spots.

Identification Tips

1. 1

   Caudal Fin

   Look for a deeply forked tail fin. This is a primary characteristic distinguishing it from most other trout species.

2. 2

   Spots

   Observe the pale, irregular spots on a darker body, head, and fins. These spots are typically lighter than the background color, unlike the dark spots on a lighter background often seen in brown trout or rainbow trout.

3. 3

   Adipose Fin

   Confirm the presence of a small, fleshy adipose fin between the dorsal and caudal fins, characteristic of salmonids.

4. 4

   Mouth

   Note the large mouth that extends well past the eye. The absence of teeth on the vomerine shaft helps distinguish it from true trout.

5. 5

   Body Shape

   Its torpedo-shaped, robust body is indicative of a powerful predator adapted to open water.

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