Antarctic Icefish has clear blood

The crocodile icefish or white-blooded fish (Channichthyidae) comprise a family of notothenioid fishes found in the Southern Ocean around Antarctica.

They are the only known vertebrates to lack hemoglobin in their blood as adults.

Icefish blood is colorless because it lacks hemoglobin, the oxygen-binding protein in blood.

All icefish are believed to be piscivorous but can also feed on krill. Icefish are typically ambush predators; thus, they can survive long periods between feeding and often consume fish up to 50% of their own body length.

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Icefish Chionodraco hamatus

To compensate for the loss of hemoglobin, icefish have larger blood vessels (including capillaries), greater blood volumes (four-fold those of other fish), larger hearts, and greater cardiac outputs (five-fold greater) compared to other fish.

Source / Image Courtesy

The icefish (Channichthyidae, crocodile icefish, white blooded fish, Antarctic icefish)