Human skin darkest brown to the lightest pinkish-white hues. Human skin shows higher variation in color than any other single mammalian species and is the result of natural selection. Skin pigmentation in humans evolved to primarily regulate the amount of ultraviolet radiation (UVR) penetrating the skin, controlling its biochemical effects. The actual skin color of different humans is affected by many substances, although the single most important substance determining human skin color is the pigment melanin. Melanin is produced within the skin in cells called melanocytes and it is the main determinant of the skin color of darker-skinned humans. The skin color
Biological pigment absorbance maximum, changing the different color pigments. In lobsters, there are various types of astaxanthin-protein complexes present. The first one is crustacyanin (max 632 nm), a slate-blue pigment found in the lobster’s carapace. The second one is crustochrin (max 409), a yellow pigment which is found on the outer layer of the carapace. Lastly, the lipoglycoprotein and ovoverdin forms a bright green pigment that is usually present in the outer layers of the carapace and the lobster eggs. Tetrapyrroles are the next most common group of pigments. They have four pyrrole rings, each ring consisting of CHNH. The main role