Leucophores

Leucophores are reflective pigment cells found in the skin of a variety of animals, including some fish and cephalopods. They produce white coloration by reflecting ambient light rather than by pigment absorption, resulting in a diffuse white appearance that can change with lighting and viewing angle.

Structurally, leucophores contain crystalline or granular deposits that scatter light. In many species these deposits are purine crystals such as guanine, organized to maximize diffuse reflection. This makes leucophores functionally different from pigment-based cells that store colored pigments.

Leucophores commonly occur as patches or along lines on the body and can contribute to camouflage by disrupting the silhouette or by blending with lighted backgrounds. They may also participate in signaling or modulate brightness when combined with other light-regulating cells such as iridophores or melanophores.

Leucophores are often categorized as a type of reflective chromatophore, distinct from pigment-containing cells. In cephalopods, leucophores are one of several specialized skin elements that enable rapid changes in appearance, alongside chromatophores and iridophores.

The name leucophore derives from Greek leuko, 'white', and phore, 'bearing'. Leucophores have been described in various teleost fishes and some cephalopods, illustrating the diversity of light-reflecting skin cells among animals.