Figure 2 in The shell-eyes of the chiton Acanthopleura granulata (Mollusca, Polyplacophora) use pheomelanin as a screening pigment

Figure 2. Absorption spectra of the pigment that we extracted from the valves of the chiton Acanthopleura granulata. The black line represents freshly extracted pigment. The grey line represents the same sample of pigment after it had been digested in alkaline hydrogen peroxide for 14 h. Note that digestion by hydrogen peroxide causes: (1) the absorption peak in the visible wavelengths to drop and shift towards shorter wavelengths; and (2) the appearance of degradation products that absorb strongly in the UV wavelengths. Both of these observations are consistent with the degradation of pheomelanin by hydrogen peroxide.