Can't breed artificially. Eel fry can't be artificially propagated because their living habits are special, and it is difficult to simulate their living environment artificially, so it is naturally difficult to reproduce. Eels have a unique habit of fresh water migration. They lay eggs and hatch in the sea, mate in land and fresh water rivers, and then return to the sea to breed their offspring. For a long time, it is not easy to master their life rules, so eels cannot be raised artificially. Eels grow in rivers on land, and when they mature, they migrate to spawning sites in the ocean to lay eggs.