David Attenborough visits the Comoro Islands looking for the coelacanth.
The local villagers are the world experts in catching them.
David holds a dried coelacanth and talks about how it uses its fleshy-lobed fins to swim and to clamber about on the seabed.
It is unusual for a coelacanth to be caught alive, but while the BBC were in the Comoros one was landed, so they put it in back the sea to film. 350 million years ago, fish with fins like the coelacanth's were swimming about and some had descendants which came out on to land.
One or two coelacanths are caught every year by the locals. They don't taste nice, but they can be sold to scientific institutions and make the lucky fisherman rich.