This kind of fish is also called flounder. Its body is black and flat, with two eyes on one side of its body. It has high nutritional value and good health preserving effect, which is of great benefit to maintaining human health.
Fish can't be eaten dark. There is a black film on both sides of the abdominal cavity of fish, which is the most smelly and earthy part and contains a lot of lipid-like, lysozyme and other substances. You'd better get rid of the black clothes before cooking fish. Membrane structure metabolism is slow, and toxins are easy to accumulate on the membrane.