Ocellated icefish live deep underwater in the cold oceans surrounding the Poles. They have clear blood. If you remember your childhood biology classes, you should remember that this kind of makes no sense. After all, blood is red because of hemoglobin — the iron-rich protein that carries oxygen around in your blood stream. No hemoglobin, no oxygen. No oxygen, dead fishies. Right? Popular Science explains how ocellated icefish get around this little conundrum.