what are the two respiratory pigments other than man haemoglobin

Respiratory pigments are molecules that help in transporting gases required or produced during respiration inside the cells. Mammals have mainly haemoglobin, a globular protein that imparts red color to the blood as respiratory pigment. Other repiratiory pigments are haemocyanin (blue in colour when oxygenated ), haemerythrin and chlorocruorin. They are not found in humans but mostly in invertebrates.