King Salmon

The largest and most sought-after of Pacific salmon, the king salmon, goes by many names, including the Chinook salmon, blackmouth, or Tyee. King salmon hatch in freshwater, migrate to saltwater to develop, and eventually return to freshwater to spawn. Anglers prize king salmon for their excellent taste, size, and high degree of difficulty to catch. 

5 King Salmon Facts

• The king salmon is the largest Pacific salmon species and the largest species in the genus Oncorhynchus. 
• These fish are born in freshwater, develop in saltwater, and then return to freshwater to spawn. 
• Unlike most other fish, king salmon only spawn once in their lives, and males typically outnumber females during the spawning season. 
• Babies are known as alevin immediately after hatching, when they are still living in their gravel nest. 
• They play an important role in the culture and traditions of several Native American or Chinookan peoples in the Pacific Northwest of the United States, hence why some people refer to the fish as Chinook salmon. 

Classification and Scientific Name

The king salmon (Oncorhynchus tshawytscha) belongs to the salmonid family Salmonidae. Its close relatives include trout, char, freshwater whitefishes, lenoks, taimens, and graylings. They are the largest species in the genus Oncorhynchus, which contains five other Pacific salmon species as well as several species of Pacific trout. The genus name Oncorhynchus derives from the Greek words ὄγκος (ónkos), meaning “lump” or “bend,” and ῥύγχος (rhúnkhos), meaning “snout,” which references the characteristic hooked snout that males in the genus develop during the mating season. Meanwhile, the king salmon’s species name tshawytscha stems from its Russian common name чавыча (chavycha). 

People refer to king salmon by a wide variety of names that vary depending on the region. The Chinookan people of the Northwest Pacific often called them Tyee salmon, which means “chief.” As a matter of fact, this fish featured so prominently in Chinookan culture that today it is often referred to as the Chinook salmon in North America. In Canada, they go by the name Quinnat salmon or spring salmon, while in some parts of the United States, people refer to king salmon as blackmouth or chrome hog.

King Salmon Appearance 

The king salmon is the largest species of Pacific salmon and the largest species in its genus. Adult fish typically measure between 24 and 36 inches long but can grow to a maximum of 5 feet long. On average, they weigh from 10 to 50 pounds but can weigh up to 130 pounds. For the majority of their lives, king salmon have predominantly silver scales with hints of blue-green on their back and white bellies. They have characteristic silver tails with black dots and a distinctive black gum line, hence their common name, blackmouth. When they return to freshwater to spawn, they undergo a radical transformation. Their silver scales turn dark and take on a red, olive-brown, or purplish hue. Additionally, the males develop a hook on the upper jaw, while the females feature a blunt nose and enlarged midsection. 

Distribution, Population, and Habitat

You can find king salmon throughout the North Pacific Ocean. Their range extends from California to Alaska in North America and across the Bering Strait to northern Japan and eastern Russia. In recent years, they have also been introduced to other regions, including New Zealand, the Great Lakes in the United States, and parts of Argentina and Chile. Most king salmon are anadromous, which means they split their lives between freshwater and saltwater. The baby salmon hatch in freshwater, migrate to saltwater to develop, and then return to freshwater as adults to spawn. Adults tend to prefer deep, fast-moving freshwater streams for spawning, while the young salmon typically stick to cover as they slowly make their way out to sea. 

Predators and Prey

The list of predators changes over the course of their lives. When they are young, king salmon are preyed upon by striped bass, whiting, mackerel, and seagulls. However, juveniles have fewer natural predators once they reach the open ocean. Still, they must contend with larger ocean predators, including sharks, seals, and orcas. Once they return to freshwater, mature fish don’t have to fear other fish. At this stage, their list of predators changes once again and includes a variety of formidable animals, including eagles, terns, cormorants, bears, and otters. Bears, in particular, can devastate salmon populations as a single adult bear can catch and eat anywhere from 10 to 20 salmon per day.

Just as a king salmon’s predators vary depending on its age, so too do its prey. As juveniles, they primarily eat insects and small crustaceans. Common prey include flies, grasshoppers, crickets, beetles, spiders, plankton, shrimp, and krill. Meanwhile, adult king salmon hunt for larger prey. Fish such as herring, sandlace, and pilchard make up the bulk of their diet, but they will also eat squid, shrimp, and even small birds. 

Reproduction and Lifespan 

The spawning season for king salmon normally takes place between September and December. These fish prefer to spawn in deep, fast-flowing freshwater rivers and can travel up to 900 miles to reach their spawning grounds. This migration often proves too much for many salmon, who succumb to predators or sheer exhaustion on their journey. Once they reach their spawning location, they dig a gravel nest called a redd to hold the eggs. Females may guard the nest for up to 25 days, but the eggs will incubate for three to five months before they hatch. 

Once the baby king salmon — known as alevin or fry — hatch, they remain in freshwater for 12 to 18 months as they slowly make their way to the open ocean. Most remain in the ocean for a few years to grow and mature, but a few populations return to freshwater to spawn after just one year. King salmon normally reach sexual maturity around three to four years old, but sometimes don’t sexually mature until almost eight years old. 

King Salmon in food and cooking

According to many critics and professional chefs, king salmon is the most delicious and prized of all salmon species. It has a bold, buttery taste and thick, smooth texture that distinguishes it even from other popular salmon, like sockeye and coho. This fish is very nutritious and features high levels of omega-3 fatty acids, protein, vitamin B12, niacin, phosphorus, selenium, and thiamine. You can prepare king salmon in many ways, including braising, baking, grilling, frying, and steaming. They can withstand high temperatures, thanks to their high fat and oil content, and their thick, meaty texture means that they don’t easily break apart. While it does not need much preparation to enhance its flavor, it also pairs well with sauces and marinades. 

King Salmon Population

This fish easily ranks as the least abundant of the Pacific salmon species. This likely has to do with the fact that they mature more slowly than most other salmon. While most king salmon mature within three to four years, they can easily take up to eight years to mature. As a result, any one of a number of factors can adversely affect populations, especially if they occur during the spawning season. Some of the challenges that king salmon face include habitat loss or modification, over-harvesting, and hydropower projects. Although most populations worldwide appear stable, several show visible signs of decline. Despite these declines, the IUCN lists the king salmon as a species of Least Concern.