08-05-2017, 10:57 AM
I am very interested in the beautiful colors caused by the pigmentation of these shells. There hasn't been a lot of research into the exact nature of these pigments. Eumelanin (from the oxidation of the amino acid tyrosine) is known to produce the blacks & browns in some shells. The color red, as in Conus viola, could be caused by either of 2 very different pigments: protoporphyrin IX is red & forms very stable red complexes with elements like iron & zinc; and pheomelanin, which is similar to eumelanin with the addition of the amino acid cysteine to form the red polymer that is also found in humans with red hair. As this shell contains both red & black pigmentation, I suspect that the pigments involved are eumelanin & pheomelanin.