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Chum Salmon Oncorhynchus keta

Typical: 24–28 in, 8–15 lb

Quickest tell: A spotless back and tail combined with a thin caudal peduncle and white-tipped anal/pelvic fins separate chum from spotted pinks/coho and from spotless sockeye (use gill-raker count to split chum from sockeye).

• No distinct spots on back or tail
• Silver at sea; spawners show purple/green vertical 'calico' bars
• Whitish tips on anal and pelvic fins
• Narrow caudal peduncle (thin tail base)
• Large, often white-rimmed pupil/eye

Full Chum Salmon guide — season, gear and rules →

Coho Salmon Oncorhynchus kisutch

Typical: 20–26 in, 4–8 lb

Key field mark: Coho has a WHITE gum line (the reliable tell) with tail spots on the upper lobe only; Chinook has a black mouth WITH black gums and spots on both tail lobes; steelhead has a fully white mouth and gums.

• Chrome silver with a metallic blue-green back
• Black spots on the back and the UPPER lobe of the tail only
• Dark/gray mouth interior but a WHITE gum line at the tooth bases
• 12-15 anal fin rays
• Broad, only slightly forked tail
• Typically smaller and slimmer than a Chinook

Full Coho Salmon guide — season, gear and rules →

When Each Is Running July — current month highlighted

Where Chum Salmon and Coho Salmon Overlap

Both run in Alaska — Southcentral & Southeast — that is where telling them apart actually matters.

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