How to Identify Pacific Salmon

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

Physical Characteristics

Body shape

torpedo

Coloration

Ocean-phase salmon are typically silvery with darker backs (blue-green to black). Spawning-phase coloration varies dramatically by species and sex, often becoming vibrant red, green, or mottled, with males developing pronounced humps and kypes (hooked jaws).

Scale type

cycloid

Mouth position

terminal

Distinctive features

Adipose fin present (small, fleshy fin between dorsal and caudal fins), Forked caudal fin (tail fin), Small, embedded scales, Vomerine teeth present (on the roof of the mouth), varying in number and arrangement by species, Pyloric caeca present (finger-like projections at the junction of the stomach and intestine), varying in number by species

Dorsal fin

Single dorsal fin, typically with 10-16 soft rays. An adipose fin is present posterior to the dorsal fin.

Tail fin

Strongly forked caudal fin, providing powerful propulsion.

Pectoral fin

Paired pectoral fins, typically with 13-16 rays.

Distinctive fins

Pelvic fins are abdominal, located well behind the pectoral fins. Anal fin typically has 13-19 soft rays.

Identification Tips

1. 1

   Tail Spotting

   Chinook salmon typically have spots on both upper and lower lobes of the caudal fin, while Coho salmon usually have spots only on the upper lobe. Sockeye salmon generally lack spots on the tail.

2. 2

   Gum Line Color

   Chinook salmon have a black gum line where the teeth meet the jaw, while Coho salmon have a white gum line.

3. 3

   Scale Size

   Pink salmon have very small scales compared to other Pacific salmon species.

4. 4

   Spawning Morphology

   Males of most species develop a pronounced kype (hooked jaw) and often a dorsal hump during spawning. Sockeye males turn brilliant red with green heads, while Pink males develop a very large, distinctive hump.

5. 5

   Pyloric Caeca Count

   This internal feature can be used for definitive identification in some cases (e.g., Chinook: 140-185; Coho: 45-80; Sockeye: 60-115; Pink: 180-210; Chum: 130-180).

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