Did You Know Nemo Is Hermaphrodite?

Hermafrodites are animals which have both female and male reproductive organs. In many cases invertebrates and molusca are hermaphrodites. Also some species of fish can be hermaphrodites, but they have other methods for reproducing. Fish have the so called protogynous or sequential hermaphroditism. That is phenomenon where male has the ability to change to female and vice versa.

So, these fish can change their sex from male to female (protandry); from female to male (protogyny), or from female to hermaphrodite (protogynous hermaphroditism). In nature there have many examples of protogyny. Clownfish (like Nemo from the Pixar movie) and the Indo-Pacific cleaner wrasse are protogynous. Clownfish live in coral rows and in groups consisted of two large fish and many small fish. The large fish are the only sexually mature fish in the group and the other small fish are males. If the large fish splits from the rest of the group for some reason then the strongest male will change its sex to female and it starts to grow much faster. This way the clownfish species is maintained.

Another good example for protogynous is the Indo-Pacific cleaner wrasse. They live in groups and forms harems. In the group there is one larger male and smaller female fish. If the male splits from the group, then one female fish becomes male. It develops male organs within only two weeks.

Fish evolved to change its sex to keep their species. Many fish species are hermaphrodites because of that.