<P> Almost all vertebrates , including all mammals and humans , have red blood cells . Red blood cells are cells present in blood in order to transport oxygen . The only known vertebrates without red blood cells are the crocodile icefish ( family Channichthyidae ) ; they live in very oxygen - rich cold water and transport oxygen freely dissolved in their blood . While they no longer use hemoglobin , remnants of hemoglobin genes can be found in their genome . </P>
<P> Almost all vertebrates , including all mammals and humans , have red blood cells . Red blood cells are cells present in blood in order to transport oxygen . The only known vertebrates without red blood cells are the crocodile icefish ( family Channichthyidae ) ; they live in very oxygen - rich cold water and transport oxygen freely dissolved in their blood . While they no longer use hemoglobin , remnants of hemoglobin genes can be found in their genome . </P>
where are red blood cells found in the body
where are red blood cells found in the body
blood
blood