The hawksbill turtle was thought to be the first reptile scientists had seen with biofluorescence - the reflection of blue light as a different colour, National Geographic reported.
Marine biologist David Gruber, of City University of New York, was in the Solomons in late July to film biofluorescence in small sharks and coral reefs.
During a night dive the fluorescent turtle suddenly came into view, looking like a spaceship, with a patchwork of neon green and red over its head and body, he said.
