Bigeye tuna

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Name Bigeye tuna
Other name `Ahi tuna, mabachi (pacific big eye tuna)
Latin name Thumus Obesus
Japanese name (please see detail below)
Kingdom Animalia
Phylum Chordata
Class Actinopterygii
Order Perciformes
Family Scombridae
Subfamily Scombrinae
Tribe Thunnini
Species T. Obesus
Genus Thunnus
Subgenus Thunnus

Flavor & Texture
Either Pacific or Atlantic Bigeye tuna have similar color; red bright for akami (lean) part. Bigeye tuna is more meaty texture compare to yellowfin tuna. Also, bigeye tuna has darker color. The texture, taste and flavor depends on the size and where they catch it. Generally, the belly part (toro) has very buttery part when the fish is big enough. The part close to the head (o-toro) is the fattiest, oily, and must be consumed raw. It is almost impossible to cook o-toro part. Medium toro or chu-toro is located slighly above the belly. It is less oily and has excellent texture; soft, not too buttery, but a little fishy. Please remember, bigeye tuna has higher fat content compare to yellowfin.

Closer to the tail, the meat has more tender and crunchy texture compare to belly part. Most of the belly parts have pink color and the rest are red (darker than yellowfin). The best part of tuna is halfway to the two-third way close to the tail.

The neck part contains so much oil. It is hard to process this part as a sushi part because the size, buttery texture with fishy smell and taste.

Bigeye tuna has been sold in fresh, frozen, CO2 frozen, superfrozen style. Indeed, it will give you wide variety of color, texture between them.

Bigeye tuna is vunerable species. Fishing process is highly regulated by government. Their weight can reach 400 lb. They are available year round. However, the peak availability are October to April.

Japanese name

  • Akami (赤身): top loin
  • Ōtoro (大とろ): fattiest portion of the belly - contains almost 40% fat
  • Toro (とろ): fatty tuna / belly.
  • Chūtoro (中とろ): medium-fat belly (usually above the belly) - contains 15-20% fat
  • General tuna - マグロ
  • Pacific big eye tuna - まバチ

There are many bluefin tuna available. However, pacific bigeye tuna is available around Hawaii, California, US Pacific Island, near Japan. They can be catched by pole, troll, longline, and purse seine methods.

Sushi Preparation
To prepare the fish (bone, skin and blodeline out) is hard to do it in restaurant. Special knife and cutter are needed to cut this fish to the smaller part. Tuna butcher is required to process this size of fish.

Let's start with tuna part. If you defroze a frozen tuna, just put it the frozen bag into cold running water. There are two styles to cut the fish; cross (opposite) the white line or remove the white line. You should taste if the white line is too chewy or not before cutting. Never re-froze the defroze tuna.

The belly part is very soft and easier to break. Therefore, use the sharpest knife. Cut while it is still cold (not frozen). Beware that this part usually more fishy than the regular part of tuna.

High quality protein, fat content (some part), selenium, phosphorus and potassium. Good fat content. It has low in saturated fat, however, it has high mercury content.

Pacific big eye tuna has many different size and source. Therefore, the nutrition fact below may vary depends on those aspect.

Nutrition Fact 100 grams +3.5 oz
Calories 115
Protein (g) 24
Fat (g) 1
Saturated fat (g) <1
Sodium (mg) 37
Cholesterol (mg) 67
Source of information:

Wikipedia, Chefsource,

Bigeye tuna measurement From left:yellowfin tuna, big eye tuna, CO2 treat yellowfin toro, big eye o-toro. Honshu Sushi, Jersey City, NJ From left:yellowfin toro (CO2), big eye chu-toro (with skin), big eye tuna, yellowfin tuna. Honshu Sushi, Jersey City, NJ  

A tiny note:

The review about the taste above is a general review. There is no fish taste the same. The weather, size, quality, the source of the fish and how the sushi chef prepare them are important aspects to the taste and texture. We try to write as accurate as possible. Therefore, we are looking forward to the reader to participate in the discussion/comment to add/adjust/revise those review. Please mention when, where and specific detail how you review the fish.