clownfish:

Clownfish, also known as anemonefish, exhibit a fascinating reproductive behavior known as sequential hermaphroditism. This unique characteristic is observed primarily among fish species inhabiting coral reef environments. In the case of clownfish, all individuals are born as males, carrying both male and female reproductive organs. Initially, clownfish develop into males … [Read more...] about The Male Clownfish: A Surprising Ability to Change Their Sex into Female