Blackfin Icefish

The blackfin icefish is a fish native to the cold waters of the Southern Ocean around Antarctica, notable for lacking hemoglobin in its blood, the only vertebrate known to do so as an adult. Its blood is nearly colorless as a result, and the fish survives by absorbing dissolved oxygen directly through its skin and gills, aided by the naturally oxygen-rich, near-freezing water it lives in. It also lacks red blood cells and scales, giving it a pale, almost translucent appearance.