Steelhead Trout vs Rainbow Trout – What’s The Difference?

Steelhead and rainbow trout are both popular fish people love to eat. They’re similar to each other making some people wonder the differences between the two. Therefore, let’s answer the question, what is the difference between steelhead trout and rainbow trout.

The difference between steelhead trout and rainbow trout is steelhead is found in fresh and saltwater while rainbow trout remain in freshwater. Steelhead trout grows to 27″ and 20 pounds. Rainbow grows to 11-18″ long and weighs 2-8 pounds. Steelhead tastes more fishy and stronger than the milder rainbow.

This article will compare both trout tastes, textures, cooking methods, costs, mercury levels and whether one can substitute for the other in recipes. In addition, I’ll do a side-by-side comparison of their nutrients, habitats, size, weight and more.

Steelhead Trout vs Rainbow Trout: Habitats, Size, Weight, Appearance

What is the difference between the two trout?

The average steelhead trout is longer and weighs more than rainbow trout. Rainbow trout has more color with olive to dark blue and silver coloring while steelhead trout is silvery. Rainbow trout is found in freshwater while steelhead is found in fresh and salt water. Steelhead lives 11 years compared to 7 years for rainbow.

Scientific Classifications, Families, Species

Both trout are from:

The salmonidae family
Oncorhynchus genus
The species O. mykiss. (oncorhynchus mykiss)

Habitats

While fishing rainbow trout can be found in tributaries (rivers and streams) or lakes in North America. Some of the rivers and streams where freshwater rainbow are found flow into larger rivers or streams but not into the ocean.
While fishing steelhead can be found in rivers, streams or lakes in North America. They migrate to the Pacific Ocean and return to the freshwater tributaries to spawn.

Both trout are hatched in freshwater streams, rivers and lakes. They start their lives the same way. Rainbow trout remain in the freshwaters and never leave. After 1-3 years the steelhead trout start migrating to the sea.

Steelhead may spend up to five years in the saltwater and when the time comes they return to the freshwater area to spawn. Unlike salmon which only do this once, they migrate and spawn several times.

Rainbow trout were introduced to the Great Lakes in 1895. They are not native to the lakes. They grow larger than the ones native to the streams and rivers. For this reason some people will call them steelheads.

Steelhead trout’s fun facts:

They have been known to jump as high as 11 feet in the air.
Steelhead can accelerate from 0-25 miles per hour in one second.

Rainbow trout in their habitat.

Colors

On the back the rainbow trout’s colors range from brown to olive to dark blue. The sides are silvery to pearl white. They have a pinkish to red lateral line from the gills down. The body has black spots.
Steelhead are silvery or brassy in color. There are black dots and a fainter reddish lateral line from the gills down.

Appearance

Rainbow trout is the typical long, narrow body shape and has two dorsal fins.
Steelhead trout’s appearance is more streamlined with a rounder head and two dorsal fins.

Size and Weight

Rainbow trout grows an average 11-18″ in length and weighs 2-8 pounds.
Steelhead grow to an average 27″ in length and weighs an average 20 pounds if spending more time in the ocean.

Some steelhead spends more or less time in the ocean affecting their size:

One-salt or half pounders are in the ocean approximately one year and weigh 2-6 pounds.
Two-salt are in the ocean approximately two years and weigh about 10 pounds.
Three, four and five-salt spend approximately up to five years in the ocean and weigh 20-30 pounds.

Age

Rainbow trout averages 7 years but the maximum known age is 11 years.
Steelhead lives up to 11 years.

Diets

During their younger years and spawning stages, both trout have the same feeding habits. When the steelhead trout migrate to the ocean, their diets change with their surroundings as more fish are available in greater numbers.

For this reason, steelhead grows and weighs more the longer they stay in the ocean. They consume the following diet:

Sardines
Herrings
Shrimp
Crabs
Zooplankton
Mollusks
Squid
Plus everything in the rainbow’s diet below when in the freshwater.

Rainbow trout’s diet is more limited and can only consume what is available in the freshwater areas. They consume the following diet:

Crustaceans
Mollusks
Gobies
Fish eggs
Nymphs
Sunfish
Shiners
Minnows
Insects

Fishing

Simple Fishing Tips

The trout fishing season may vary depending on your State. Some have trout fishing all year in lakes and ponds and in inland streams from April to October. Others may open and close different months.

Always check your required local fishing rules and regulations. Prior planning and research will lead to a more successful fishing trip.

In many places late spring is the best time to go fishing for trout. As the temperatures warm up competition from other anglers increases.

Trout are more active between 34 and 67 degrees. In the 40s feeding increases. Under cloud cover and shady areas may be better.

Fishing rainbow or different trout species like lake trout, river trout, brook trout, cutthroat trout may have different rules, guides, fishing gear, rod, fishing line, fly tying and fly fishing tips.

Trout fishing.

Trout Taste and Textures

One of the most important things people takes into consideration when choosing a fish or while fishing is the trout taste. Let’s compare the taste of each trout.

Steelhead trout and rainbow trout both have a mild flavor although steelhead has a more fishy taste. Rainbow trout has a slightly nutty flavor steelhead doesn’t possess. Steelhead is firmer and less flaky than rainbow trout.

Rainbow trout’s texture is delicate, soft and flaky when cooked.

Steelhead has a mild taste and a slight fishy flavor. It’s less fishy than the similar tasting salmon. Steelhead’s texture is more firm than tender with some flakiness. A farm raised steelhead tastes milder, non-fishy and more like a rainbow trout.

Both trout have different diets which can affect how they taste and why one trout is larger than the other.

I conducted original research on taste by polling my clients, readers and members of food groups. I asked them which trout, steelhead trout vs rainbow trout, tastes better?

54% said they preferred rainbow.
46% said they preferred steelhead.

To conduct more research on taste, I setup a blind taste taste at home. Both fish were cooked and seasoned the same way. 75% chose the rainbow due to its less fishy trout flavor.

The video explains how to cook steelhead trout.

Steelhead and Rainbow Substitutions

When preparing recipes for dinner it’s not always possible to locate the type of fish in a market or while fishing. If you have only one type of trout you may wonder if you can substitute one trout for the other.

Steelhead trout can substitute for rainbow trout due to their similar mild tastes although steelhead’s flavor is slightly fishier if wild caught. Both trout have a firm texture allowing for similar cooking methods in recipes. Both trout can be grilled baked, roasted, poached, fried or seared.

The best steelhead substitutes include the following:

Rainbow trout
Halibut
Arctic char
Halibut
Flounder
Salmon
Cod

The best rainbow trout substitutes are:

Salmon
Arctic char
Bluefish
Steelhead trout
Mahi mahi
Mackerel

When substituting either trout try to stick to the following:

Same size and weight.
Stick with similar fillets, whole fillet or cross section.
Stick with skinless or skin when the recipe calls for one.
Texture is more important for certain cooking methods. Like using a firmer texture when grilling¹.

Trout dinner with rice and broccoli. — Trout dinner with rice and broccoli

Check out the best replacements for trout in my article, Trout Replacements: The 12 Best Healthy Substitutes.

How Much Does Steelhead Trout and Rainbow Trout Cost

The costs for most fish will vary depending on how the fish are caught. A steelhead caught in the ocean will definitely be more expensive than farm-raised trout.

When purchasing trout fish, be sure to check the label to see if it is wild-caught or farm raised. Therefore, let’s take a close look at the costs of each trout.

Steelhead trout and rainbow trout are similar costs. The average cost for farm raised rainbow trout is $9.99 per pound while the average cost for farm raised steelhead trout is $9.99 per pound. The cost will vary depending on location, whether the trout is farm-raised or wild-caught, fresh or frozen.

Some stores may have subtle differences between the two trout or run the occasional sale.

To conduct research about the costs I visited various stores and checked their prices.

First, I checked the local Freshdirect online supermarket for the current trout prices.

Fresh fish, farm steelhead trout
- $15.99 per pound
Wild rainbow trout butterflied fish
- $11.99 per pound

I then checked my local Shoprite supermarket:

Fresh, farm raised rainbow trout fillet fish
- $9.99 per pound
Fresh, farm steelhead fillet fish
- $9.99 per pound

Kevin Garce checking prices of catfish and seafood in his local supermarket. — Checking prices of catfish bass and seafood in my local market

Steelhead Trout and Rainbow Trout: Mercury Levels

The EPA and FDA have issued warnings and suggestions regarding mercury levels in fish and how often they should be consumed². This is especially important for young infants, developing children and pregnant women.

They established a list of best fish, good choices and fish to avoid based on their mercury levels. Let’s examine the levels of both trout.

Steelhead trout contains more mercury than rainbow trout. Rainbow and fresh water trout are listed on the FDA’s best choices of fish to consume regarding their mercury levels. Steelhead trout is listed on the good choices list.

Always check with a physician prior to eating new foods, trout or changing your dietary habits especially if you’re getting yours by fishing.

Steelhead Trout and Rainbow Trout Nutrition Value

The following table is a side-by-side comparison of all the nutrients per four ounces of trout:

Nutrient	Steelhead Trout, raw (4 Ounces)	Rainbow Trout, raw (4 Ounces)
Calories	160	135
Fat	7.0 g	3.9 g
Saturated Fat	1.5 g	0.8 g
Cholesterol	65 mg	67 mg
Protein	22 g	23 g
Sodium	60 mg	35 mg
Omega-3	1.09 g	0.79 g
B-6	0.4 mg	0.4 mg
B-12	5.0 mcg	5.0 mcg
Thiamin	0.13 mg	0.13 mg
Riboflavin	0.11 mg	0.11 mg
B5	1.0 mg	1.0 mg
Iron	0.8 mg	0.7 mg
Niacin	6.1 mg	6.1 mg
Folate	13.6 mcg	13.6 mcg
Potassium	422 mg	545 mg
Magnesium	37 mg	35 mg
Phosphorus	317 mg	307 mg
Calcium	25.7 mg	75.9 mg
Zinc	1.4 mg	1.2 mg
Selenium	26.0 mcg	14.3 mcg

Nutrient Sources³ ((Nutrition Value: Fish, raw, wild, rainbow, trout))

Both fish contain a good number of minerals and vitamins. At first glance it’s difficult to determine which fish provides more. Therefore, let’s take a close look at which trout is healthier.

Steelhead trout is healthier due to its higher percentage of heart healthy omega-3 fatty acids and minerals. They provide more iron, magnesium, phosphorus, zinc and selenium. They both contain a similar number of B vitamins, protein and cholesterol.

Rainbow trout is no slouch either and contains a similar variety of vitamins and minerals. They provide a higher percentage of calcium, potassium and contains less calories and fat.

Although the lesser fat is due to its less omega-3s. Omega-3 fatty acids are important for your health. I’ll explain why in the next section about both fish health benefits.

Steelhead Trout and Rainbow Trout Health Benefits

B Vitamins

Of the seven B vitamins listed in the table above, both trout contain a similar amount of each. The B vitamins in the table include B6, B12, B5, B1 (thiamin), B2 (riboflavin), B3 (niacin) and B9 (folate).

B vitamins help support the following:

Cardiovascular disease
Red blood cells
Brain function
Nerve function
Digestion
Energy levels

Steelhead Health Benefits

Omega 3 Fatty Acids

Steelhead trout provides 1.09 grams of omega-3 per four ounces raw. It contains approximately 40% more which leads to the question, why does omega-3 fatty acids matter so much?

It’s because omega-3 fatty acids are heart healthy and help keep arteries healthy. The omega-3s in trout may help with the following:

Keeping bad cholesterol low.
Keeping good cholesterol high.
Reducing inflammation.
Reducing plaque build-up.
Lowering triglycerides
Help keep the heart rhythms more normal.

DHA and EPA, two of the fatty acids, are associated with lowering blood pressure and improving the health of blood vessels ((National Center for Biotechnology: Marine Omega-3 Supplementation and Cardiovascular Disease)).

Studies suggest omega-3s can help reduce joint pain and stiffness in people with rheumatoid arthritis. They may also boost the effectiveness of anti-inflammatory drugs.

Magnesium

Both trout offer a decent number of magnesium per four ounces. Adding magnesium to your diet could be instrumental in improving sleep related issues like insomnia. Magnesium relaxes and calms the whole body including the blood vessels ((National Institutes of Health: Magnesium)).

More so, it helps keep blood pressure levels balanced and stable. A recent study researched 22 studies and concluded magnesium supplementation decreased diastolic and systolic blood pressure⁴.

Magnesium helps control muscle and nerve function, blood sugar and blood pressure. In the muscles and heart, magnesium competes with calcium to help the muscles relax after contracting.

When the body is low in magnesium, calcium can over stimulate the heart muscle’s cells causing a rapid or irregular heartbeat.

Selenium

Selenium is an underreported nutrient. I’m unsure why because studies⁵ show selenium may help to protect the following:

Heart disease
Thyroid
The immune system
Cognitive issues

Rainbow Health Benefits

Calcium

Rainbow trout provides 75.9 mg of calcium per four ounces. Calcium is important for blood pressure and the heart.

Harvard Health reports calcium helps maintain blood pressure because it helps to control the relaxing and tightening of blood vessels⁶. Calcium also helps the following:

Build and maintain strong bones.
Muscles need calcium to function properly.
Improve nerve function.

Potassium

Since the recommended daily amount is 4,700 mg, both trout provide an excellent number. Potassium is beneficial for reducing sodium intake.

It helps the body reduce fluids and rids excess sodium ((American Heart Association: How Potassium Can Help Control High Blood Pressure)). This process helps to reduce blood pressure.

The more potassium you consume, the more sodium your body will lose. Consuming too much sodium or not enough potassium throws off the delicate balance the kidneys need to remove the excess water⁷.

According to Harvard Health, a number of studies have shown a connection between low potassium levels and increased blood pressure⁸.

Steelhead and Rainbow Trout FAQs

Do rainbow trout turn into steelhead trout?

Some rainbow trout turn into steelhead trout but not all. The rainbow trout migrating to the ocean from the freshwater environments turn into steelhead trout. The rainbow trout remaining in the rivers and streams do not turn into a steelhead trout.

Are steelhead trout and rainbow trout genetically the same?

Steelhead trout and rainbow trout are both genetically the same. Both trout are the same species of fish but live a much different life after hatching. Steelhead and rainbow trout belong to the same salmonidae family, Oncorhynchus genus and Oncorhynchus mykiss species.

As a Certified Health Coach, many of my clients ask me about seafood. In addition to coaching clients about steelhead and rainbow trout, I’ve purchased, researched and consumed both fish for over 20 years.

If you have any questions about this article or other featured content, don’t hesitate to email and notify us. You can find an email on our contact page. We’ll do our best to reply as soon as possible.