Ocellated icefish (Chionodraco rastrospinosus) Transparent blood fish. Ocellated icefish do not have hemoglobin the blood is colorless.

Use the term “red-blooded” as code for virile, vital or robust, and the ocellated icefish is bound to feel a little insulted, to say nothing of left out. After all, how much more vital can you get than surviving in the depths of the Antarctic’s icy waters? And the icefish manages swimmingly, even without the hemoglobin necessary to give red blood to every other creature on Earth that has bones. Scientists would like to get to the bottom of how the icefish operates on transparent blood (a larger heart and no scales to impede oxygen absorption are two possible explanations). – MSN