Involved in oxygen transport from gills to the various peripheral tissues. Hb1 is a heterotetramer of two alpha-1 chains and two beta-1 chains; Hb2 is a heterotetramer of two alpha-2 chains and two beta-1 chains. Red blood cells. Hb1 and Hb2 display a low, effector-enhanced Bohr effect and no Root effect. Belongs to the globin family.