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Scientific Name: Thunnini
Order: Scombriformes
Family: Scombridae with three tribes of Bonitos, Mackerels, and Tunas
Tribe: Thunnini, Tunas with five Genera and fifteen Species
Genus: Allothunus, (1 species) Species: Fallai, Slender tuna,
Genus: Auxis, Frigit tunas (2 species)
Genus: Euthynnus, Little tunas (3 species)
Genus: Katsuwonus, Skipjack tuna (1 species) Species: Pelamis
Genus: Thunnus, albacore, bluefin, yellowfin (8 species)
Market Tuna
Of the fifteen species of tuna, there are four which are most commonly seen in the fish market: albacore, bluefin, skipjack and yellowfin.
Mercury in Tuna
The mercury level in tuna increases as the fish ages and as it becomes larger, thus the longer lived the fish is the more likely it is to have higher level of mercury toxin in its meat. The length of life of the most common tuna caught for human consumption are:
Albacore 9-15 years, 15-90 pounds
Bluefin 20-40 years, 800-1496 pounds
Skipjack 6-10 years, 6-100 pounds
Yellowfin 5-8 years, 6-445 pounds
Albacore Tuna
Albacore tuna is often called white tuna when it is canned and it is the species with the lightest meat.
Albacore has three times the level of omega-3s than does skipjack.
However, the mercury level in albacore tuna is three times as high as that of skipjack tuna. Therefore, albacore tuna should not be eaten often.
Bluefin Tuna
Bluefin is the tuna of choice by many, usually because it has a little more fat and thus more flavor. Mature bluefin tuna have dark red meat, similar to the color of beef. The bluefin is the largest species growing up to 1600 pounds.
Most of the bluefin catch is exported to Japan and sold at premium for sashiimi.
Skipjack Tuna
Also known as aku or arctic bonito, the skipjack tuna, like the name, is seen jumping or skipping over the ocean surface. This tuna is the smallest species seldom growing larger than 25 pounds and is normally canned, being called chuck light tuna. It has the strongest flavor and highest fat content.
Dried boninto is called Katsuobushi in Japan where it is used.
Yellowfin Tuna
Also known as ahi tuna, yellowfin is less expensive than bluefin, but is nearly as good in taste. Although often canned, it is much easier to find at the market than bluefin. This tuna is pale pink with a flavor slightly stronger than albacore.
Yellowfin tuna, like albacore, has a higher mercury level.
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