The mullet is also called black fish, snakehead, snakehead, etc. It is a fish of the order Perciformes and the family Snakehead. There is an allusion about mullet, called "mullet food". It is said that mullet will go blind for a period of time after spawning, thus losing the ability to hunt. After hatching, the young fish will take the initiative to swim into the mother's mouth because they are worried that the mother will starve to death. In the past, people believed that this was a sign of filial piety. The mullet was also regarded as a "filial piety fish". In some places, a big mullet would be given to the elderly when celebrating their birthdays to express the younger generation's respect for the fish. Filial piety to elders.

But there is no scientific basis for this allusion, and mullet will not go blind after spawning. The scientific explanation is that snakehead fish are carnivorous fish, very ferocious in nature, and will even kill each other among themselves. Once they are hungry, they will fill their stomachs with their own eggs.

Filial piety is a behavior that only higher animals have. This behavior should be possessed by strong thinking ability. The mullet does not have this kind of thinking. It is just a man-made behavior towards the mullet eating its seeds. Given the meaning of filial piety. The reasonable reason for the behavior of mullet larvae should be that the parent fish holds the larvae in their mouths to protect them after encountering an enemy, or it is a normal predatory behavior, eating weak fry, which also serves the purpose of controlling the population.