First, the body size is huge.

Bluefin tuna's size is very huge, generally adult bluefin tuna's weight can be close to more than 500 kg, that is to say, the general fishing method can not catch, you need to be equipped with a crane to be able to, the other problem is that the bluefin tuna's speed is also very fast, as the saying goes, fat people are not afraid to be afraid of fat people are also very agile, the fishing is difficult to be so big! Not to mention the need to catch it alive, and even if you catch it alive, you basically can't farm it, the overhead is too high, and the feed just can't afford to feed it.

The second is the inability to transport.

Bluefin tuna's physiological structure and sharks are very similar, they need to pass through the constant swimming, so that seawater passes through their gills to breathe, once they stop swimming will soon die because of asphyxiation, don't believe it you can go to a variety of oceanographic museums to see, there is no display of sharks is also the reason for this. Even if we catch a live bluefin tuna, we simply can't bring it back alive, there is not that much water storage space in the cabin for it to breathe, not even in an underwater hollow cabin, the bluefin tuna swims very fast, just like a sports car with no brakes, and even if it doesn't die of asphyxiation, it will crash itself to death in the cabin.

Third, the environment.

Bluefin tuna belongs to the genus Tuna, which is a deep-sea fish that generally lives in the deep sea where water pressure is very high. Deep-sea fish in order to fight against the water pressure in the deep sea close to a meal, the internal skeleton is generally bent cut pliable, muscle tissue and skin fiber tissue is generally not very hard, it looks like the bluefin tuna hard and upright, in fact, is a paper tiger a touch on the broken. Bluefin tuna's body cells will be filled with water, used to maintain the balance of water pressure inside and outside, once captured by humans out of the water, immediately burst the internal organs and die. Deep-sea fish meat is delicious for the same reason, but also led to the deep-sea fish skin is fragile, a slight wound will lead to infection, touch injury is directly fatal, so do not say that artificial breeding, even live capture is very difficult, at present, the world does not have a country or organization to try to artificial breeding.