Figure 1
From: Regulation of red fluorescent light emission in a cryptic marine fish

Red fluorescence in the iris of Trypterygion delaisi . Illustration of fluorescence in Tipterygion delaisi A. Individual showing red fluorescent eye-ring (= iris) under natural conditions (at -23 m, upside down under shady overhang, STARESO, Corsica, using a Nikon D700 DSLR, image taken without flash or filter and manually adjusted white balance). B and C are two pairs of images, each of which was taken with a 5 s delay showing rapid changes in the brightness of iris fluorescence in the laboratory using blue illumination and a red filter for viewing.