Marty’s photo of the day #4910: For yesterday’s photo of the day, I featured a bluespotted grouper that produced the illusion of bioluminescence. Today’s photo is even more extreme. These redfin butterflyfish appeared to be bioluminescent near their pectoral fins. But again, it’s an illusion. Instead, they have fluorescent pigments in their skin that absorb blue or ultraviolet light and re-emit it as longer wavelengths.
Photographed last month in the Raja Ampat of Indonesian New Guinea.