Atlantic titi barrier such as a river and are thus completely genetically isolated from one another). Distinctions between each of the "Callicebus" subspecies are based on coat color. The evolution of these coat colors is termed metachromism. The pigments are produced by melanocytes which deposit the pigments into the medulla of growing hair so that the hair grows with the color of that distinct pigment. The characteristic pigment of the "Callicebus" is eumelanin (dark brown or black) found in the iris, skin, and hair (usually on the forehead, crown and tail). Atlantic titis are opportunistic feeders. In other words, they eat based
Pigment Pigment A pigment is a material that changes the color of reflected or transmitted light as the result of wavelength-selective absorption. This physical process differs from fluorescence, phosphorescence, and other forms of luminescence, in which a material emits light. Most materials selectively absorb certain wavelengths of light. Materials that humans have chosen and developed for use as pigments usually have special properties that make them useful for coloring other materials. A pigment must have a high tinting strength relative to the materials it colors. It must be stable in solid form at ambient temperatures. For industrial applications, as well as