Fish are the most diverse group of vertebrates
on the planet from the gigantic whale shark

to the tiniest minnow.

They re over 32,000 species of fishes that
are known and new ones are being discovered

all the time.

That s more species than all of the amphibians
and reptiles and birds and mammals put together.

Because of their diversity, fish have evolved
varied reproductive strategies, ranging from

the expected to the very bizarre.

Whether it s they re born male and turn
female, born female turn male, or change back

multiple times, fish have found a way to utilize
sexual reproduction to their advantage in

pretty much every way you can imagine.

This sort of mixing and matching, sometimes
I ve thought of it as sexuality a la carte.

Take a little female characteristic here,
a male characteristic there and this is

very common in nature.

Sex change as a normal mode, the reproductive
strategy for animals, is something that, I

would say the general public doesn t know
anything about.

And they re absolutely fascinated when they
hear about it for the first time.

People are shocked almost some times, greatly
surprised, entertained by what these animals do.

Most people have seen the movie Finding
Nemo, you know with the little anemone fish,

and his mother disappears and his father raises
him.

What would happen in nature is that, when
Nemo s mother disappeared, Nemo s father

would change sex and become a female, Nemo
would mature into a mature male, and they

would form a mating pair.

Wait, WHAT?

What really happens when it s time for love
in the sea?

Why do some fish species change sex?