How To Identify A Coho Salmon: A Complete Guide

Two commonly caught species of salmon are coho and Chinook. Anglers must be able to correctly identify the species of salmon they are trying to catch because fishing laws and seasons often change depending on the species.

Along the Pacific coast, the coho salmon, which is sometimes called the silver salmon, is one of the most sought-after game fish. Proper identification is crucial, as misidentification can lead to violations of fishing regulations. This guide covers everything you need to reliably identify coho salmon.

Coho Salmon Description

Coho salmon are medium-sized salmonid fish that exhibit the following characteristics

Streamlined, torpedo-shaped body profile.
Blue-green to silver coloration on the back and upper sides.
Lower sides ranging from silver to brilliant red.
Black spots on back and upper lobe of the tail fin.
Lower fins with some black pigmentation.
Adults range from 17-38 inches long and 6-15 pounds.
Males develop a hooked jaw called a kype when spawning.

Coho Salmon vs Chinook Salmon

Chinook and coho salmon appear similar but can be distinguished by

Spots: Coho have spots on the back and upper lobe of the tail fin. Chinook have spots on both lobes.
Gumline: Coho have a light colored gumline on the lower jaw. Chinook have uniformly dark gums.
Size: Chinook grow larger, up to 50+ lbs. But size ranges overlap.
Tail: Coho tail fin rays have hardened segments that can be felt. Chinook lack these segments.

Identifying Coho Salmon In Saltwater

When salmon enter the ocean, they take on a uniform silver coloration Spot pattern and jaw characteristics are the only reliable ways to identify coho in marine habitats

Look for spots only on the back and upper tail lobe.
Check for a white or faded gumline on the lower jaw.
Do not rely on size or color alone for identification.

Identifying Spawning Coho Salmon

When coho salmon move to coastal streams and rivers to spawn in the fall, they get bright colors for breeding:

Head and back turn dark blue-green.
Flanks exhibit vibrant red to purple hues.
Males develop a pronounced kype hook jaw.
Retain spots on back and upper tail lobe.
Light lower jaw gumline persists.

Tips For Accurate Identification

Follow these best practices when identifying coho salmon:

Carefully examine the lower jaw gumline for light coloration.
Check for spots only on the upper rear tail fin.
When in doubt, compare to reference photos or illustrations.
Release the fish if unable to positively identify the species.
Learn the key distinguishing traits between coho and other salmon.
Understand regulations for correctly identifying “in-the-round” fish.
Ask experienced anglers for help or contact local fishery authorities.

Accurately identifying salmon protects fragile fish stocks and prevents illegal harvest of prohibited species. Consult local fishing regulations for specific requirements.

Coho Salmon Habitat and Range

Coho salmon have a complex life cycle that involves migration between freshwater and marine environments:

They are born in gravel-bottomed streams and rivers where they spend their first year.
Juvenile “smolts” outmigrate to the ocean from spring through fall.
Adults return to natal waters between July and December to spawn.
Die after spawning between November and January.

The coho salmon ranges along the Pacific coast from Monterey Bay north to Alaska:

Abundant runs occur in coastal watersheds from Northern California to British Columbia.
Major sport fisheries exist in Oregon, Washington and Southern British Columbia.
Landlocked populations exist in the Great Lakes and Siberia.
Declined from historical abundances but many streams maintain runs.

Accurate identification allows fishery managers to monitor populations, set harvest regulations, and protect wild coho salmon.

How To Safely Release Coho Salmon

Properly releasing coho salmon after capturing them is important for their survival:

Carefully remove the hook using pliers or hook removers. Avoid excessive handling.
For deeply hooked fish, cut the line near the mouth. The hook will dissolve over time.
Revive fish in water until they are able to swim upright and powerfully.
Release fish immediately without removing them from the water if possible.
Support the body horizontally, do not hold vertically by the gills or jaw.
Move them gently back and forth to flow water over the gills.
Let the fish swim away on its own after recovering strength and equilibrium.

With careful handling and identification, released coho salmon can survive to complete their life cycle.

Why Correct Identification Matters

Properly identifying coho salmon is critical for ethical and sustainable sport fishing. Consider the following:

Many salmon runs are under pressure and quotas are tightly controlled.
Regulations for harvest, size limits and catch methods vary by species.
Accidental catch of imperiled salmon species is harmful to wild populations.
Misidentification can lead to citations, fines and loss of fishing privileges.
Releasing the wrong salmon decreases survival of that individual.

Learning the distinguishing features of coho salmon benefits anglers, fishery conservation, and responsible stewardship of natural resources.

how to identify a coho salmon

Do’s and don’t’s for salmon identification:

DO look at the lower jaw’s gum line to tell a salmon apart. It is the single best feature to use. Also, this is the trait that police officers are most likely to look at to decide if there has been a violation and if a ticket should be issued.
DO carefully release any salmon if you can’t be sure of its species and think it might be illegal to keep it.
DO NOT use body color or spots to figure out what kind of salmon you caught in the ocean it is. Salmon that are still in the ocean will not have the same colors they will have when they get to estuaries and rivers. There are big differences in spots and color between species of ocean salmon, even though they are all mostly silver.
DO NOT use the presence or absence of a hooked nose to help you identify someone. A hooked nose is a common secondary sexual trait of male salmon as they get older. It is found in all species.
DO NOT use the salmon’s size to figure out what kind it is. The Chinook is the biggest of our salmon, and sometimes fish over 50 pounds are caught. However, most Chinook caught in the ocean are between 25 and 30 pounds. But coho have been seen that are between 12 and 15 pounds.

Coho “silver” salmon (Oncorhynchus kisutch)

Lower jaw of a coho salmon. Note the distinct banding pattern of dark to light to dark.

The lower jaw has a color that has a clear banding pattern. There is a dark band around the outside of the base of the teeth, a white or very light band at the base of the teeth, and another dark band inside the base of the teeth.
If you run your fingernail along the top of the fin ray of the tail, you can feel bone segments in the fin rays.
Teeth are sharp and firmly set in the jaw.
The upper lobe of the tail may or may not have “round” spots on it. Sometimes, coho will have spots on both ends of their tail.
There may or may not be “small” spots on the back.

Note that the coloration at the base of the teeth is consistent with the area inside and outside the mouth.

Identifying the differences between Pink (Humpey), Silver ( Coho), and King (Chinook) Salmon

FAQ

How do I know if I have coho or Chinook?

Chinook are larger and deeper bodied than coho and steelhead. They have a dark mouth with black or dark colored gums. They often have “peanut” shaped spots that are larger than spots on coho and steelhead, mature fish are usually brownish green, although males can be pure (body and head) red during spawning window.

What is the identification of coho salmon?

In mature male coho salmon, the upper jaw forms an elongated hooked snout and the teeth become greatly enlarged. The male is generally brighter than that of the female and is characterized by the dorsal surface and head turning bluish-green.

What does a coho salmon look like?

Commonly called silver salmon, coho have dark metallic blue or greenish backs with silver sides and a light belly. While they are in the ocean, they have small black spots on their back and on the upper lobe of the tail. The gumline in the lower jaw has lighter pigment than on Chinook salmon.

How is coho salmon different from regular salmon?

Coho: Coho is milder and often lighter in color. Pink and Chum: These are smaller fish and are most often used for canned or smoked salmon and are good budget choices. Atlantic: According to the Food and Agriculture Organization (FAO), the Atlantic species make up 90% of the farmed salmon market.

How do you identify a Chinook & coho salmon?

Two commonly caught species of salmon are coho and Chinook. Fishing regulations require anglers to correctly identify salmon species as restrictions such as legal lengths and seasons often vary based on the species. DO use the gum line on the LOWER jaw for identifying a salmon. It is the single best feature to use.

How much does a coho salmon weigh?

Coho Salmona.k.a. Silver Salmon Oncorhyncus kisutch (on-cor-AIN-cus KEY-such) PHYSICAL CHARACTERISTICS Average weight: 8 – 12 pounds Average length: 24-30 inches Record setting Coho adults are as long as 42 inches and weigh as much as 36 pounds.

Is coho salmon hard to identify?

Illustration by Joseph R. Tomelleri © Oncorhynchus kisutch – scientific name Coho salmon can be hard to identify. Learn more about identifying Atlantic salmon, Chinook salmon, coho salmon, rainbow (steelhead) trout and brown trout.