>Icefish blood is colorless because it lacks hemoglobin, the oxygen-binding protein in blood. Channichthyidae are the only known vertebrates to lack hemoglobin as adults.
https://en.m.wikipedia.org/wiki/Channichthyidae
>Icefish blood is colorless because it lacks hemoglobin, the oxygen-binding protein in blood. Channichthyidae are the only known vertebrates to lack hemoglobin as adults.
https://en.m.wikipedia.org/wiki/Channichthyidae