Tuna's body structure is quite special, must swim fast, in order to maintain the body's supply. It swims with its mouth open all the time, so that when the water passes through the gills, it can breathe aerobically, and once it stops swimming, it will suffocate and die. Because of this, they will not rest at night, but the speed of swimming will slow down a little.
Tuna swim very fast, the average speed of up to 30-50 km per hour, if it is high-speed swimming, or even to 160 km per hour, is one of the fastest swimming marine animals, only sharks and large dolphins can be comparable. It mostly feeds on marine animals, and its high swimming speed can also ensure that it can successfully hunt, so as to satisfy its metabolism.
Tuna has abundant muscle and vascular plexus on both sides of the body, and its body temperature can be about 9 ℃ higher than the water temperature, and its body temperature can reach about 33-35 ℃. Because of the large amount of myoglobin in its meat, the color is mostly red, which is different from many fish. This fish usually inhabits 100-400 meters deep in the sea, and its reproductive capacity is very strong.
Because tuna has to swim fast all the time and only moves in the deep sea area, the meat is delicious and there is no pollution. It is a very healthy food. Its protein content is about 20% and its fat content is very low, so it is also called submarine chicken. In addition to rich in amino acids, there are vitamins and other minerals, which have high nutritional value.
