The crocodile icefish or white-blooded fish (Channichthyidae) are a family of perciform fish found in the cold waters around Antarctica and southern South America. Water temperature can drop to -1.9 °C (the freezing point of seawater) in the Antarctic sea but stays rather constant. There are about 25 currently recognized species of crocodile icefish. They feed on krill, copepods, and other fish.
Icefish reach total length of 25–75 cm.
Their blood is yellow because it contains no hemoglobin. Red blood cells are usually absent and if present are rare and defunct. Oxygen is dissolved in the plasma and transported throughout the body without the hemoglobin protein. The fish can live without hemoglobin because of their low metabolic rates and the high solubility of oxygen in water at the low temperatures of their environment. However, the oxygen carrying capacity of their blood is less than 10% that of their relatives with hemoglobin.