Directly with a knife to scrape off can be.

In fact, the layer of black film can be eaten directly, the layer of black film, want to tear tear, lazy tear do not tear, it does not have any impact on health.

This layer of black membrane in the fish belly is called "peritoneal dirty layer", also known as the "endothelial dirty layer", which exists in the fish between the abdominal wall and viscera, is a normal physiological structure. The role of the membrane is to wrap most of the organs in the abdominal cavity, have to absorb the impact, the effect of protecting the viscera, it can also secrete mucus to wet the surface of the organs, reduce friction between the organs.

So, this membrane can play a role in lubricating and protecting the internal organs. Moreover, not only fish have, many higher vertebrates, including human beings, have such a membrane in the abdominal cavity, the main role is also to protect the internal organs and lubrication.

Expanded information:

In fact, not all the fish belly of this layer of the membrane is black, also There are other colors, the color of the membrane in the fish belly is determined by the pigment content of the fish body. In order to eat the carp, for example, its body pigment cells have four kinds, respectively, melanin, yellow pigment, red pigment and guano pigment.

There are melanin cells deposited on the surface of the dirty layer of the peritoneum, and guano pigment cells deposited in the wall layer of the peritoneum. Different fish species, it is the peritoneal visceral layer and peritoneal wall layer pigment cell distribution is not the same, so it will show different colors. Scientists have conducted a survey of 78 species of fish, the results found that not all fish peritoneal color is black, blackened only 20 kinds.

People's Daily Online - Is the black membrane in the fish belly toxic