The Channichthyidae (The Crocodile Icefish)
The Channichthyidae is an amazing (but strange) fish that lives off the cost of Antarctica and south off South America. For starters, it has no hemoglobin. Hemoglobin is a metalloprotein that contains iron and is “vital” to the oxygen transport systems of most vertebrates. It is also the protein that makes blood rust-red. Somehow the Icefish does without it. As a side effect of the absence of hemoglobin, the fish has colorless organs! As well, they do not have very many red blood cells. The crocodile icefish is, also, scaleless. That is because they need to absorb oxygen from their environment. The scales would hinder their absorbing properties. Another interesting fact about the channichthyidae is that they have developed an antifreeze protein that is able to grab on to ice crystals to stop them from growing bigger. The fish is part of a family (perciform fish) that ALL have the antifreeze protein/gene that helps them survive. All in all, the channichthyidae is an extraordinary fish and a good example of evolution to give itself an advantage over the environment.
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