Millions of people around the world rely upon them for food - but fish are also pretty cool creatures. Literally.
The cold-blooded aquatic vertebrates often play a very important role in ecosystems - whether in rivers, lakes or oceans. Here's an automated compilation of content relating to fish.
It's long been known that lizards drop their tails to avoid being eaten by predators, but little was known about the Madagascar fish-scale gecko and its ability to shed its skin when under attack - until now. With me to talk about this strip-teasing gecko and the researchers amazing discovery is Ph.D student Mark Scherz.
Much of the salmon on our tables this festive season could come from Norway - or Scotland. But chances are it won't be wild, but farmed. Is this a sustainable way to keep us supplied with healthy fish? Critics aren't so sure. "Living Planet" pays a visit to Scotland to hear both sides of the story. Gudrun Heise presents this report by Gabor Paal.