- Clownfish: Clownfish are sequential hermaphrodites, which means that they can change their gender from male to female. This happens when the dominant female in a group dies, and the most dominant male will then become female.
- Snails: Some snails, such as the ramshorn snail, can change their gender from male to female or vice versa depending on the needs of the population. For example, if there are too many males in a population, some of them may switch to female in order to reproduce.

- Wrasse: Wrasse are another type of fish that can change their gender. In some species, the dominant male will become female if the current female dies. In other species, wrasse can change their gender multiple times throughout their lives.
- Freshwater pipefish: Freshwater pipefish are fish that live in freshwater streams and rivers. They are also sequential hermaphrodites, and the most dominant male will become female if the current female dies.
- Horseshoe crabs: Horseshoe crabs are not fish, but they are marine animals that can change their gender. Horseshoe crabs are protandric hermaphrodites, which means that they start out as males and then switch to female later in life.
The ability to change gender is an adaptation that helps some animals to survive and reproduce. For example, clownfish can change their gender to ensure that there is always a dominant female in the group. This is important because the dominant female is the one who lays the eggs. In wrasse, the ability to change gender allows for more flexibility in the social hierarchy. This can be helpful in populations where there are a lot of males or a lot of females.
The ability to change gender is a fascinating phenomenon that is still not fully understood. Scientists are still learning about the different ways that animals can change their gender and the reasons why they do it.