In both the ocean and fresh water, fish degeneration often occurs. After they change gender, they can still reproduce as usual.

Pseudanthias fish in the family Serranidae? Pseudanthias

The family size of the fiery red Pseudanthias living in the Red Sea is relatively large. Even the smaller Pseudanthias There are also up to a dozen members in the family of squid, and the family of the larger squid family consists of dozens of fish. Among so many family members, only one is male, so it naturally becomes the head of the family, while the other female fish have the ability to change into male fish. When the male fish in the family disappears or dies due to some accident, a female fish in the family will become a male fish and begin to assume the role of the head of the family.

Furthermore

Research shows that eels that hatch from fertilized eggs into young eels are generally female and can lay eggs. However, after laying an egg once, their reproductive system A sudden change occurs and the ovaries turn into fertilized eggs and can produce sperm. At this time, the eel becomes a male and fertilizes the eggs produced by the female eel. Zoologically, this is called "male precocious puberty", but this phenomenon is not common.