Different light colours allow visualization of otherwise "invisible" animals. A (Upper left panel). Illumination of an unfixed brittlestar with UV light. Please note the small mite indicated by the arrow. B (Upper right panel): Zoom of A. C (Lower left panel) and D (lower right panel). An arm of the brittlestar under white (left) and UV light (right). Please note, the two brown eyes (arrow), the only visible part of the mite under white light.