The swordfish belongs to the class Osteichthyes, the family Xiphiidae, and is a large fish. The classification of fish can start with their living environment, such as living in the sea is marine fish, living in freshwater is freshwater fish. In this respect, swordfish belong to marine fish. They are widely distributed in the world, including the Pacific Ocean, the Indian Ocean and the Atlantic Ocean.
In terms of latitude, swordfish are mainly distributed in tropical and subtropical oceans, that is, in oceans with relatively low latitudes. Swordfish are also found in temperate zones, but not as much as in tropical and subtropical zones. From the depth point of view, the swordfish is distributed in the deeper part of the ocean, belonging to a deep-sea fish.
As mentioned above, swordfish belong to marine fish. In the long course of their life, swordfish have adapted to the marine environment. If they are suddenly allowed to live in fresh water, they will not be able to adapt. Swordfish itself lives in the depths of the ocean, where the pressure is relatively large, if the pressure is very small in fresh water, it may cause blood vessels to burst because of pressure problems. In addition, the salt concentration in seawater and freshwater is very different, and swordfish have adapted to the high salinity environment. If they are suddenly allowed to live in fresh water, their metabolic function will be problematic, and they may even die in a short time.
