How to Identify Coho Salmon

To identify Coho Salmon (Oncorhynchus kisutch), look at these key features.

Physical Characteristics

Body shape

torpedo

Coloration

Ocean phase: Silvery sides, dark blue to greenish-blue back. Spawning phase: Males develop a reddish-maroon coloration on their sides, dark backs, and a hooked snout (kype). Females are typically duller red/brown. Juveniles (smolts) are silvery with parr marks (vertical bars) on their sides.

Scale type

cycloid

Mouth position

terminal

Distinctive features

Small, irregular black spots on the back and upper lobe of the caudal fin (tail fin), White gums at the base of the teeth, with black pigment on the tongue and roof of the mouth (distinguishes from Chinook), Relatively large eyes compared to other salmon species, Males develop a pronounced kype (hooked jaw) during spawning

Dorsal fin

Single dorsal fin, followed by an adipose fin (fleshy, rayless fin characteristic of salmonids).

Tail fin

Forked caudal fin, with small, irregular black spots primarily on the upper lobe.

Pectoral fin

Paired pectoral fins, typically clear or slightly dusky.

Distinctive fins

Adipose fin present; anal fin typically has 12-15 rays.

Identification Tips

1. 1

   Spots on Tail Fin

   Coho salmon typically have small, irregular black spots only on the upper lobe of their caudal fin. Chinook salmon have spots on both lobes.

2. 2

   Mouth Coloration

   When the mouth is open, Coho salmon have white gums at the base of their teeth, but black pigment on the tongue and roof of the mouth. Chinook salmon have black gums and mouth lining.

3. 3

   Anal Fin Rays

   Count the rays in the anal fin. Coho salmon typically have 12-15 rays, while Chinook salmon usually have 15-19.

4. 4

   Spawning Coloration (Males)

   Spawning male Coho develop a distinctive bright reddish-maroon body coloration and a pronounced kype (hooked jaw).

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