Is Ahi Tuna Meat? Decoding the "Red Meat of the Sea"

January 3, 2026 •

4 min read

Despite its deep red color and firm, beef-like texture, ahi tuna is biologically and legally classified as a fish. The common phrase, “red meat of the sea,” contributes to the confusion, causing many people to wonder, is ahi tuna meat?

Quick Summary

Ahi tuna is a fish, scientifically distinct from red meat, though its high myoglobin content gives it a similar color and meaty consistency prized in many culinary applications.

Key Points

Ahi Tuna is a Fish: Biologically, ahi tuna is a fish and not a type of red meat, though its high myoglobin content gives it a dark red color similar to beef.
Myoglobin Causes Red Color: The deep red flesh is not blood but a protein called myoglobin, which stores oxygen for the fish's active muscles.
Meat-like Texture: Its firm, dense texture is why it's often called the "steak of the sea" and is prepared similarly to beef steaks.
Rich in Omega-3s: Unlike red meat, ahi tuna is an excellent source of heart-healthy omega-3 fatty acids.
Lean and High in Protein: It is a lean, high-protein food, making it a popular alternative for those looking to reduce their saturated fat intake.
Sourcing is Important: Overfishing is a concern for tuna populations, so choosing sustainably-sourced ahi is crucial.

What Exactly is Ahi Tuna?

Before answering the central question, it's important to understand what ahi tuna is. The Hawaiian term “ahi” refers to two distinct species of tuna: yellowfin (Thunnus albacares) and bigeye (Thunnus obesus). Both are large, predatory fish found in tropical and subtropical oceans worldwide. Their firm flesh, rich flavor, and deep color have made them a staple in high-end cuisine, particularly in dishes like sushi, sashimi, and seared tuna steaks.

The Scientific Reason Ahi Tuna is Not Red Meat

To get a clearer picture, it helps to examine the scientific differences between fish and what is traditionally considered red meat. The distinction primarily comes down to biological classification and anatomy.

Myoglobin: The Protein Behind the Color

The deep red, almost beef-like color of ahi tuna comes from a high concentration of myoglobin in its muscle tissue. Myoglobin is an oxygen-binding protein, and its presence is necessary for muscles that require a lot of oxygen for sustained activity. Since tuna are highly active, fast-swimming predators, their muscles are rich in myoglobin, causing the flesh to be red. This contrasts with most other fish, which have less myoglobin and appear white, and also differs from red meat of land mammals which is also high in myoglobin.

Warm-Blooded vs. Cold-Blooded

While most fish are cold-blooded, tuna and certain shark species are an exception. Tuna possess a unique adaptation that allows them to maintain a body temperature higher than the surrounding water, making them partially warm-blooded. This endothermy allows them to swim faster and hunt more effectively in deeper, colder waters. This physiological trait further contributes to their unique, meat-like properties but does not change their fundamental classification as a fish.

The Culinary Comparison: Ahi Tuna as the "Steak of the Sea"

The firm, dense, and meaty texture of ahi tuna is what most strongly links it to traditional red meat in the culinary world. Many recipes for ahi tuna steak involve searing it quickly over high heat, similar to how a beef steak is prepared, leaving the center rare or medium-rare. This preparation method highlights the fish's buttery flavor and tender texture, which can be very appealing to those looking for a healthier alternative to beef. The mild flavor of ahi, especially when seared correctly, can be a great entry point for those who are typically hesitant to eat fish.

Ahi Tuna vs. Beef Steak: Nutritional Comparison

For those weighing their options, a nutritional comparison reveals significant differences, particularly in fat content and specific vitamins.


Feature	Ahi Tuna (per 3 oz serving)	Beef Steak (per 3 oz serving, lean)
Protein	~21-23 grams	~21-23 grams
Saturated Fat	Very low	Higher
Omega-3 Fatty Acids	Excellent source	Not a significant source
Iron	Present, but less than beef	Excellent source
Vitamin B12	High concentration	High concentration
Vitamin D	High concentration	Low concentration
Selenium	Excellent source	Low concentration

Ahi Tuna and Dietary Categories

Beyond biological and culinary distinctions, dietary practices and beliefs also influence how ahi tuna is viewed.

Pescatarian Diets: For pescatarians, ahi tuna serves as a primary source of animal protein, as it is a fish and not the meat of a land animal.
Religious Practices: In some religions, such as Catholicism, fish is differentiated from meat for specific periods like Lent.
Weight Loss and Healthy Eating: For many, swapping red meat for lean fish like ahi tuna is a strategy for weight management and improving heart health due to its high protein and low-calorie, low-saturated-fat profile.

Sustainability and Responsible Sourcing

With the growing demand for ahi tuna, concerns about overfishing and sustainability have become more prominent. Consumers should look for reputable sources and certifications to ensure their ahi tuna is caught responsibly. Initiatives from organizations like the Marine Stewardship Council (MSC) help certify sustainable fishing practices, preserving tuna stocks for the future.

Conclusion

In summary, while ahi tuna shares certain characteristics with red meat, such as its rich color and firm texture, it is fundamentally a fish. The comparison is understandable given its high myoglobin content and preparation methods, but it is incorrect to classify it as a type of red meat. Whether you enjoy it seared like a steak or raw in a poke bowl, ahi tuna stands on its own as a nutritious, versatile, and unique part of the seafood world.

The "Other Red Meat" of the Sea

This article has explored the distinctions and similarities between ahi tuna and red meat, but the final verdict is clear. While it's understandable to make the comparison, ahi tuna is a fish through and through. Choosing sustainably-sourced ahi ensures you can enjoy this culinary favorite responsibly for years to come. For more information on sustainable fishing, visit the Marine Stewardship Council.

Frequently Asked Questions

No, ahi tuna is not a red meat. Biologically, it is a fish, and while its muscle tissue has a deep red color due to high levels of the oxygen-binding protein myoglobin, this does not make it a land animal's red meat.

The red color in ahi tuna comes from myoglobin, a protein that stores oxygen in the muscle tissue. Tuna's active lifestyle requires a high myoglobin content, which is why its meat appears red.

Ahi tuna is often considered a healthier alternative to red meat like beef due to its high content of heart-healthy omega-3 fatty acids and lower saturated fat content. Both are excellent sources of protein.

Ahi tuna is called 'steak' in a culinary context because its firm, dense texture and appearance are similar to a cut of beef. It is also often prepared in the same way, such as by pan-searing.

No, not all types of tuna are red. Albacore tuna, often sold as 'white tuna' in cans, has a lighter, pinkish to white flesh. The color varies depending on the species and the myoglobin content of their muscles.

From a biological and legal perspective, tuna is a fish. The term 'meat' can be broadly defined as animal flesh, but tuna is specifically classified as a marine animal, or fish.

The term 'ahi' is the Hawaiian name for two species of tuna: yellowfin and bigeye tuna. Therefore, yellowfin tuna is one of the fish that can be called ahi tuna.