Salmon play a key role in maintaining the health of the Earth’s river ecosystems; they provide food for many species (including humans and bears), distribute nutrients to rivers and oceans when they die, and nitrogen released during spawning encourages tree growth. Salmon can also be obtained very the largest, with the largest salmon ever weighing nearly 100 pounds (more on this below.)
Salmon species are also revered by some Native American tribes in the Northwest as a significant part of their diet, history and culture. As with most animals hunted for food, overfishing has resulted in declines despite commercial hatcheries working hard to stabilize populations locally. Salmon are also well known for their migrations. Freshly hatched salmon must swim downstream (in some cases down to the ocean) until they reach maturity. When they are ready, they float upstream again, to where they were born, appear and die. This perilous journey has been the subject of many nature documentaries and is complicated by the presence of hydroelectric dams blocking the upstream passage.
Recently, many old and ineffective dams have been removed in the Pacific Northwest region to open rivers to natural salmon habitat. There are seven types of salmon in the world today (along with the newly discovered bonus) and they are listed below in order from smallest to largest. In this article, salmon are measured in inches for length and pounds for weight.
Bonus: Cunimasu salmon (up to 11 inches)
How shocked would you be if you stumbled upon a species that has been considered extinct for over 70 years? This is what happened to the kunimasu salmon, which was native to Lake Tazawa in northern and central Japan until 1940, when the construction of a hydroelectric dam resulted in fish deaths. Attempts to relocate the fish in 1935 were considered unsuccessful, but in 2010 Kunimasu was rediscovered at Lake Saiko (about 300 miles south). They are listed as extinct in the wild, since the emergence of the local population today became possible only thanks to human intervention; about 2,600 of them live in Lake Saiko.
There is no nutritional and habitat information available for the kunimasu as research is still pending. However, it is the smallest salmon on our list, measuring just over 30 cm in length. Kunimasu was previously classified as a subspecies of sockeye salmon, and then it was separated into a separate species. In the world of endangered wildlife, it’s always good to know that some supposedly extinct species have survived.
7. Salmon Masu (average size: 20 “, 4.4-5.5 lb) (max. Observed: 28”, 20 lb)
Masu salmon are the dominant salmon in the North Pacific Ocean near East Asia, and their range extends from Siberia to Korea, Taiwan and Japan. Like other salmon, masu usually dies after spawning and can live up to 3.5 years. Unlike other salmon, young masu can stay in the spawning area for up to three seasons before heading out to the ocean.
Masu is also known as cherry salmon because the streaks on its body turn red and crimson when the salmon reaches maturity. There are several subspecies of masu, including anadromous (freshwater born, living in seawater, freshwater spawning) and freshwater or landlocked varieties. They are currently considered endangered by the IUCN.
6. Pink salmon (average size: 20-25 “, 3-5 pounds) (max. Observed: 30”, 15 pounds)
This species, also known as pink salmon, is the most abundant salmon in the Pacific Ocean. It is commonly referred to as the smallest of the North American Pacific salmon. Habitat is extensive, with salmon found from the south, all the way to the Sacramento River, all the way north to the Mackenzie River, in northwestern Canada. Occasionally, pink salmon can be seen further south, such as the Salinas River in 2014 and the Lagunitas Creek (25 miles north of San Francisco) in 2017.
Pink salmon often change color and appearance throughout life, eventually developing a very large hump and hook-shaped jaws. According to the Alaska Department of Fish and Wildlife, young pink salmon do not naturally float. They have to float to the surface and swallow air bubbles into their swim bladder to avoid drowning. Since pink salmon was not included in the Endangered Species Act, it does not have a conservation status under the IUCN; however, other conservation organizations such as NatureServe consider the population to be stable with regional variation (critically endangered in California).
5. Sockeye salmon (medium size: 21-26 inches, 4-7 lbs) (maximum weight: 15 lbs, 3 oz)
Sockeye salmon – one of the most recognizable species on the list – is silvery in the ocean and turns bright red on its way back to its breeding grounds. The fish has also been featured in numerous nature documentaries due to its extravagant migrations (or races) that can eventually travel over 1,000 miles. Not all populations migrate to the ocean; the landlocked sockets are known as kokani and are generally much smaller than the anadromous.
Sockeye salmon feeds mainly on zooplankton and has long been a staple food for humans. Sockeye salmon are usually in declining numbers, but they are widespread in several regions and watersheds. The world’s largest sockeye salmon fishery occurs near Bristol Bay, Alaska; 63.2 million fish returned to the bay in 2021.
4. Coho salmon (medium size: 24-28 inches, 5-10 pounds) (maximum weight: 33 pounds, 7 ounces)
Coho salmon is a large species of Pacific salmon; it has silver sides and a dark blue back during the ocean phase. Like other salmon, during spawning, the physiology and color of the coho salmon change, they develop hooked jaws and red skin. Traditionally, coho salmon lived on both sides of the Pacific Ocean. More recently, it was introduced to the Great Lakes and many other bodies of water in the United States.
Most coho salmon return to spawning after three years, although sometimes two-year-old males are smaller too. Two-year-old males are referred to as “male males” and are not perceived as a threat by older and larger salmon. When the larger coho salmon fights for spawning territory, the male of the nest sometimes swims across the female’s eggs and fertilizes them, while other males are distracted. Scientists have dubbed this method “sneaking.”
3. Chum salmon (average size: 24-31 “, 6.5-12.5 lb) (Max Observed: 44”, 42 lb)
Chum salmon (also known as dog salmon, chum salmon, calico salmon, and silver salmon) are an anadromous fish found in a wide range in and around the Pacific Ocean. They make one of the longest salmon migrations and travel far up the Yukon and Amur rivers. Chum salmon have a metallic greenish-blue color along their back with black spots that make them look like coho salmon and sockeye salmon. Typical of salmon, they change dramatically as they swim upstream, eventually forming a pattern of red and black tiger stripes. Males also develop large canine-like canines and chintz color. Chum salmon usually live 3-5 years and die shortly after spawning.
2. Atlantic salmon (medium size: 28-30 inches, 8-12 lbs) (maximum observed: 63.25 inches, 74 lbs)
Belonging to the same scientific family Salmonidae, this large fish is the only salmon species in the North Atlantic and is found off the coast of Canada, the United States and Europe. Like other salmon, most populations are anadromous. Unlike Pacific salmon, Atlantic salmon do not always die after spawning and may return within a few years.
When Atlantic salmon live in fresh water, they develop blue and red spots; when they reach maturity, the spots change color to a silvery-blue cover. They are currently listed as Least Concern by the IUCN, but have not been reassessed since 1996. Restoration work is currently underway in Lake Ontario and many rivers in the northeast. In Europe, Atlantic salmon is listed as a vulnerable category by the IUCN.
1. Chinook salmon / king salmon (medium size: 36 “, 30-38 lbs) (maximum observed: 58”, 97 lbs)
Correctly named, chinook salmon (or king salmon) is the largest salmon species on Earth. It had a wide natural distribution and was successfully introduced to regions near New Zealand, the Great Lakes and Patagonia. Fish is highly valued for its nutritional value as it contains high levels of omega-3 fatty acids.
The conservation status of this species has not been assessed by IUCN. Some watershed populations appear to be declining, while others appear stable and healthy. In the Kenai River, salmon weigh on average about 37 pounds, but the largest salmon caught in sport fishing weighs 97 pounds. Chinook salmon on the Yukon River have the largest freshwater migration route in the world, traveling 1,900 miles from the river mouth to Whitehorse, Yukon.
Like many other salmon, the chinook salmon develop a pronounced hook on the jaw, called a kipe, when it approaches spawning, but can spend up to eight years in the ocean before returning to a spawning river. Interestingly, the chinook salmon’s birthplace can be traced using its earbone, just as tree rings provide information about the age of a tree. A bone called an otolith records the chemical composition of the water in which the fish spawn, showing the timeline for the evolution of that particular salmon.
World Record Salmon: Largest Ever Caught!
World record – 97 lb Chinook salmon caught in Soldotna, Alaska in 1985. The large salmon was over 58 inches long! Now, like most world records, the largest salmon has controversy and other title contenders. For example, several salmon caught and released have claimed to compete with the record, but world records rely on official measurements. There is another Chinook claim that weighed up to 125 pounds, but this has not been confirmed.
Salmon controversy
What would a list of animals be without any controversy? The salmon species listed above are often grouped together with steel trout. As the US Geological Survey explains, despite the fact that steel heads have a lot in common with salmon, they are able to repeat spawning and do not die after that. This important difference in life cycle means it is technically not salmon. There are also several species of fish called salmon but do not have the same characteristics as salmon; these include Australian salmon, Danube salmon, Hawaiian salmon and Indian salmon.
Dam failure is a matter of controversy in areas with traditionally large salmon populations due to their upstream life cycle. Dams block natural migration routes and pose a threat to species, which is why many organizations are working to dismantle old and ineffective dams. Large dams such as Bonneville have fish ladders built to mimic the rapids area. Ladders allow the salmon to swim across the dam. While successful, they also attract other predators (such as sea lions) due to the high concentration of salmon on the stairs.
Complete list of the largest salmon with scientific names
- Kunimasu salmon (Oncorhynchus kawamurae)
- Masu salmon (Oncorhynchus masou)
- Pink salmon (Oncorhynchus gorbuscha)
- Sockeye (Oncorhynchus nerka)
- Coho salmon (Oncorhynchus kisach)
- Chum (Oncorhynchus keta)
- Atlantic salmon (Salmo salar)
- Chinook (Oncoryhnchus tshawytscha)