Why do hairtail seldom appear at parties?

Hairtail caught is easy to die because the pressure changes quickly. But if it is caught by fishing, it usually swims to the surface of the water layer by itself, and it has its own process of slowly decompressing, so fishing can catch live hairtail. Hairtail caught is generally silver, and the silver "scales" outside will be completely protected. Hairtail caught rarely breaks its belly, which is very beautiful.