All those colorful little Nemos you see at the aquarium started out as males. Clownfish are born male but with both male and female reproductive organs inside. So, then how do they reproduce and make clownfish babies? The males can transform into females when mating is required!
When the alpha female of a clownfish community dies, one of the males steps it up (so to speak) and turns into a female so that mating can continue. And once they swap genders, there’s no switching back. Crazy, right?