King Mackerel vs Mackerel: What’s The Difference? We Compare

The king mackerel and mackerel have many similarities. For this reason many people discuss how they’re different. Let’s answer, what is the difference between king mackerel (kingfish) and mackerel?

King mackerel and Atlantic mackerel are different species. King mackerel are found more south than Atlantic mackerel and also on the India coastlines. King mackerel are longer and can weigh 40 pounds while Atlantic mackerel weigh 2 pounds.

This article will compare their 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 and appearance.

As a Certified Health Coach many of my clients ask about fresh fish including mackerels. In addition to coaching clients about them, I’ve purchased, researched and consumed both prior to, during and sometimes after writing this article.

King Mackerel and Atlantic Mackerel: Habitats, Size, Weight and Appearance

When someone is shopping in the market for fresh, whole fish or catching one in the water, it may not be immediately obvious which type they’re looking at. For this reason, we want to find out a simple method for identifying each one.

Let’s take a close look at how to identify each species.

To tell the difference between a king mackerel and Atlantic mackerel check their back color and body side markings. King mackerel have an olive green back, Atlantic mackerel have an iridescent blue green back. Atlantic mackerel have 20-30 wavy dark lines on their upper sides. King mackerel doesn’t have any dark lines.

Other ways to tell the differences:

King mackerels have a thin lateral line running down the body that starts high and slopes down. Atlantic mackerels have a dark, narrow, blotchy line running down the body that doesn’t slope.
King mackerels front dorsal fin has spines and the rear dorsal fin has soft rays. Both Atlantic mackerel’s dorsal fins are spiny.
Juvenile king mackerels, under 10 pounds, have yellow spots on their sides. Atlantic mackerels have no yellow spots.
Atlantic mackerels average 2.2 pounds while king mackerels can weigh up to 40 pounds.
King mackerels can be found south of North Carolina, in the Gulf of Mexico, South America and India where Atlantic mackerels aren’t found.

Scientific Classifications, Families, Species

King mackerels are from:

Family: Scombridae
Genus: Scomberomorus
Species: S. cavalla
Common nicknames: Sierra, cavalla, kingfish.

Atlantic mackerels are from:

Family: Scombridae
Genus: Scomber
Species: S. scombrus
Common nicknames: Mackerel, Boston mackerel, common mackerel, Norwegian mackerel.

Both of them are from the same family of fish but are different genus and fish species. Many times when people say mackerel they are referring to an Atlantic mackerel.

There are other mackerel species people sometimes confuse with others or think they’re the same. Let’s take a quick look at them.

Horse Mackerel

The pacific jack mackerel was originally called horse mackerel. The FDA allowed the name to be officially changed in 1948 to increase its marketability.

Sierra Mackerel

Sierra mackerel are found in the Pacific Ocean but are a different species than Pacific Chub or Pacific Jack.

Cero Mackerel

Cero mackerel are found in The Atlantic Ocean of the U.S. Atlantic coast all the way down to South American near Brazil.

Spanish Mackerel

The mackerel Spanish are found off The Atlantic coast of the United States and in the Gulf of Mexico. There are a different species than Atlantic.

Spanish mackerel’s colors are similar and kings and spaniards have the same number of fins which can lead to confusion.

Atlantic Mackerel swimming in the water.

Habitats

King mackerels habitat

They are found off the Atlantic Ocean coast of the United States, the Gulf of Mexico and South America. They are as far north as Maine and south past Florida down to Brazil. They are also found in the Indian Ocean and the coast of India.
They can be found in deeper waters from 40 to 590 feet deep.

Atlantic mackerel habitats

They are found in the western Atlantic Ocean from Canada down to the eastern coast of the United States to North Carolina. In the eastern Atlantic Ocean, they are found from Iceland and Norway and south to Mauritania.
- They are also found in the Baltic, Mediterranean and Black Seas.
They can be found in deeper waters from the surface dow to 660 feet deep. They prefer water above 40 degrees Fahrenheit.

Places where king are found and Atlantic are not found:

The Gulf of Mexico
South America
Near the coast of India

Appearance

Is their appearance the same? Let’s start with the Colors

King mackerels have an olive back, silver sides and white belly. Younger ones, under 10 pounds, have yellowish-brown spots on their sides which fade as they grow older and bigger.
- They have a similar shape and yellow markings as the Spanish Mackerel which sometimes lends to confusion.
Atlantic mackerels have an iridescent blue green back and upper sides, silvery white lower sides and belly. The top half of the body has 20-30 wavy black lines running down the length of the body.
- There’s a dark streaky line running the length of the body half way up the sides, directly under the wavy lines and blueish green coloring.

Dorsal Fins

The Atlantic mackerels two dorsal fins have spines while the king mackerel’s front dorsal is spiny (15 spines) and the second one having about 15 soft rays.
Atlantic mackerel’s dorsal fins are spaced farther.

Anal Fins

Atlantic and king mackerels only have soft rays on their one anal fin.

Tail Fins

King mackerel’s tail fin is more forked than the Atlantic mackerel’s tail fin.

Mouth

Atlantic and king mackerels have sharp teeth inside their mouth on the lower and upper jaws.
Both have a large mouth but it doesn’t extend past the eye line.

Body Shape

Atlantic and king mackerels have a long, narrow body which tapers towards the tail.

Scales

The scales on the Atlantic and king mackerels are small.

Size and Weight

King mackerels can grow to 30-50 inches long and weigh up to 40 pounds or more.
The smaller Atlantic mackerels average 12-17 inches long and weighs 2.2 pounds.

Lifespan

Both species live up to 20 years.

If you’re interested in how the Spanish mackerel compared, check out my article.

Diet

King mackerels consume the following:

Squid
Menhaden
Clupeidea
Cutlessfish
Striped anchovies
Minnows
Northern mackerel
Blue runners

Atlantic mackerels consumes the following:

Small fish
Copepods
Plankton
Krill
Shrimp
Squid

Species Resources¹ ((Mass.gov: Learn about Atlantic mackerel))

Fishing

Before going fishing and climbing into your boat, be sure to check your State park’s education programs and wildlife websites. Visitor centers are also a great place to learn about more marine life and other species.

To catch mackerel fishing, refer to the State or county for any limitations and waters where fishing may have regulations.

Many people target May and June as a good time to go fishing, this may be different depending on your area. Dawn or dusk may be a good time for fishing.

Tastes and Textures

One of the main reasons people chooses a particular food to eat is its taste and texture. After all, who doesn’t want to something they don’t think tastes good. When comparing the two species, let’s examine if they taste the same or if one is better.

King and Atlantic mackerel have a similar medium flavor taste. Their flavor is not considered too sweet or mild. Both have an oily flesh due to its higher fat content. The two have a similar firm texture which breaks apart into small flakes.

Some people find mackerel tastes more like tuna than salmon. Depending where it was caught, it may taste slightly fishy to some people. Although most people don’t think it’s too fishy.

To conduct some research, I polled clients, members of food groups I belong to and some readers. The following are the results of my poll which consisted of 26 people.

I asked which one tasted better?

73% preferred the taste of Atlantic.
15% preferred the taste of king.
12% said they had no preference between the two.

Many of the people polled mentioned they didn’t prefer king due to the higher mercury levels.

Find out what species people preferred, Atlantic or Spanish, in my article.

Substitutions

It’s not always possible to locate the type of food required for your recipe. In addition, you may have one already in the refrigerator ready to be used. This situation may make you wonder if one can substitute for the other.

Atlantic mackerel can substitute for king mackerel due to their similar medium flavors. Both fish can be cooked using similar cooking methods due to their similar firm textures. Both can be cooked by grilling, searing, frying, broiling or baking.

The king mackerel substitutes are:

Bass
Northern pike
Tuna
Bullhead
Salmon
Catfish

Atlantic mackerel substitutes include the following:

Tuna
Bass
Salmon
Bullhead
Northern pike
Catfish

When substituting always 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 grilling².

How To Cook King Mackerel

Foods For Anti Aging do not recommend consuming king mackerel due to their high mercury levels. Please see the mercury section down further in this article.

Even though, some people still enjoy eating it and try to use the smaller ones which probably contain less mercury. Some people may find it a little fishy therefore the preparation is important.

Many people soak them in milk or icy water, rinse the fillets and soak the fish again. Repeat this process until the flesh and the water become clearer.

Popular ways to cook:

Grilling
Frying
Baking
Broiling
Searing

Flavor pairings:

Lemon juice
Olive oil
White wine
Cajun
Italian dressing
Smoked paprika

The video below lets you know how to make roasted mackerel.

How To Cook Atlantic Mackerel

Popular ways to cook include:

Grilling
Frying
Broiling
Baking
Searing

Flavor pairings:

Olive oil
White wine
Lemon
Cajun
Smoked paprika

Quick Links To More Articles You May Be Interested In:

Herring vs Sardines – What’s The Difference? Let’s Compare

Pacific Cod vs Atlantic Cod – What’s The Difference?

Tuna vs Salmon: Which is Better?

Brook Trout vs Brown Trout – Let’s Compare The Differences

Cost

The prices for seafood will vary depending on how they are caught and where they are sold. When purchasing any seafood, be sure to check the label to see if it is farm-raised or wild-caught. Let’s take a close look at the prices of each one.

King and Atlantic mackerel fillets have a similar price per pound. Whole Atlantic mackerel fish costs $15.98 per pound. Whole king mackerel fish costs $13.12 per pound.

I checked the Fulton fish market online for prices:

Wild king fillet
- $18.97 per pound
Wild whole king
- $13.12 per pound
Wild whole Atlantic
- $15.98 per pound

I also checked Citarella online for prices:

Whole Atlantic
- $10.80 per pound

Kevin Garce checking the prices of mackerel and other seafood at his local market. — Checking the prices of mackerel and other seafood at my local market

Mercury Levels

The EPA and The Food and Drug Administration have issued warnings and suggestions regarding mercury levels in fish and how often they should be consumed³. This is especially important for the following:

Developing children
Young infants
Pregnant women

They established a list of the following:

Best fish
Good choices
Fish to avoid

Knowing which one of the two has a level is important especially with one of the two species.

King mackerel has more mercury than Atlantic mackerel. Atlantic mackerel is listed on the FDA’s best choices of fish regarding mercury levels. King mackerel is listed on the FDA’s choices to avoid list.

If you’re pregnant, breast feeding or has a young child, Always check with a physician prior to eating new foods or changing your dietary habits.

If you’re consuming fish from the best list, The FDA recommends eating two to three servings per week total for adults. From the good choices list, they recommend eating them once per week.

Mercury warnings can change over time or affect only a particular area or state. Please check with your local EPA and FDA for the current recommendations⁴.

I recently published an article comparing Cero Mackerel and Spanish Mackerel. You can check it out here, Spanish Mackerel vs Cero Mackerel – What’s The Difference?

Nutrition Comparison

Below is a nutrient comparison per four ounces raw:

Nutrient	King mackerel, raw (4 Ounces)	Atlantic mackerel, raw (4 Ounces)
Calories	119	232
Fat	2.3 g	16 g
Saturated Fat	0.4 g	3.7 g
Cholesterol	60 mg	79 mg
Protein	23 g	21 g
Omega-3	0.37 g	2.85 g
B-6	0.5 mg	0.4 mg
B-12	17.6 mcg	9.8 mcg
Thiamin	0.11 mg	0.20 mg
Riboflavin	0.54 mg	0.35 mg
B5	0.9 mg	0.9 mg
Iron	2.0 mg	1.8 mg
Niacin	9.7 mg	10.2 mg
Folate	9.0 mcg	1.1 mcg
Potassium	493 mg	356 mg
Magnesium	36 mg	86 mg
Phosphorus	281 mg	246 mg
Calcium	35.1 mg	13.6 mg
Zinc	0.6 mg	0.7 mg
Selenium	41.3 mcg	50.0 mcg

Nutrient Resources⁵⁶

Both of them contain a wide variety of similar nutrients. Atlantic mackerel contains more of some nutrients while king contains more of others. Many people like knowing what fish is healthier for them.

Atlantic mackerel is healthier than king mackerel due to its higher percentage of heart healthy omega-3 fatty acids and lower levels of mercury. The FDA recommends avoiding king mackerel due to its high mercury levels. Atlantic mackerel provides more thiamin, niacin, magnesium, zinc and selenium.

It’s unfortunate of the high level of mercury because it also provides many beneficial nutrients. King mackerel provides more folate, B6, B12, riboflavin, potassium, phosphorus and calcium.

The calories and fat content of Atlantic mackerel are higher, but it’s due to its heart healthy fats, particularly omega-3 fatty acids. Keep reading the next section to find out why omega-3s are considered healthy.

King mackerel dinner. — King mackerel dinner

Health Benefits

Editor’s Note: The information on FoodsForAntiAging is meant to be informative in nature and not meant to be taken as medical advice. The articles and opinions on this website are not intended to be used as as a treatment, prevention or diagnosis of health problems. Before modifying or starting any new nutritional, fitness, exercise or/and supplement routine, always check with your doctor first.

Omega 3 Fatty Acids

Atlantic mackerel provides one of the highest percentages of omega-3 fatty acids in the seafood world. It provides 2.85 grams of omega-3 fatty acids per four ounces. The fatty acids provided help keep arteries healthy and are considered heart healthy.

The omega-3s may help with the following:

Reduce plaque buildup.
Reduce inflammation.
Help keep the heart rhythms more regulated.
Lowering triglycerides.
Keeping bad cholesterol low.
Keeping good cholesterol high.

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 boost the effectiveness of anti-inflammatory drugs. In addition, they’ve been shown to help reduce joint pain and stiffness in people with rheumatoid arthritis.

I also compared Atlantic Mackerel and Pacific Chub Mackerel in a recent article. Find out which mackerel tasted better in my reader poll, Atlantic Mackerel vs Pacific Chub Mackerel: The Differences.

B Vitamins

The B vitamins provided include the following:

B1 (thiamin)
B2 (riboflavin)
B3 (niacin)
B5
B6
B9 (folate)
B12

B vitamins help support the following:

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

Magnesium

Magnesium helps to calm and relax the whole body including blood vessels. It has been shown to help improve sleep related problems like insomnia ((National Institutes of Health: Magnesium)).

Magnesium helps keep blood pressure levels balanced and stable. A recent study researched 22 studies and concluded magnesium supplementation decreased diastolic and systolic blood pressure⁷.

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.

The video explains the health benefits of mackerel, sardines, salmon and some other fish.

Selenium

Selenium is a nutrient which doesn’t receive much attention in nutrient articles. I’m unsure why many people don’t write about it more.

Many studies⁸ show selenium may help to protect the following:

Cognitive issues
Heart disease
Thyroid
The immune system

Calcium

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 vessels⁹.

Calcium also helps the following:

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

Potassium

Potassium helps the body get rid of excess sodium which helps reduce fluid build-up. The result keeps systolic and diastolic blood pressure lower ((American Heart Association: How Potassium Can Help Control High 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 water¹⁰.

According to Harvard Health, a number of studies have shown a connection between low potassium levels and increased blood pressure¹¹.

Phosphorus

Phosphorus has been shown in scientific research to help with the following:

Help the body manage and store energy.
Help the kidneys with waste removal.
Promote teeth and bone strength.
Muscle recovery after exercise.
Muscle contraction.
Promote healthy nerve conduction.

Another article I recently published, Chub Mackerel vs Jack Mackerel: What’s The Difference?