hæmacyanin

CIDE DICTIONARY

hæmacyanin, n. [Hæma- + Gr. ky`anos a dark blue substance.].

 A substance found in the blood of the octopus, which gives to it its blue color.  [1913 Webster]
" When deprived of oxygen it is colorless, but becomes quickly blue in contact with oxygen, and is then generally called oxyhæmacyanin. A similar blue coloring matter has been detected in small quantity in the blood of other animals and in the bile."  [1913 Webster]