Google translate gives us this description (from the video):
Introducing rare Japanese fish. A unique Matsukasauo. I saw it after a long time. In the old days, you could throw it into a bonfire, bake it and eat it. The scale is hard and the kitchen knife does not enter. Although small , he is very delicious. When processing, do you put a knife in the anus or cut it with scissors? For roasted and steamed fish. It is expensive as an ornamental fish because it has a rare value. It may be sold as a stuffed animal for ornamental purposes. It’s a fish like a skeleton, but it’s also called a pineapple fish.