by Tsing Mui on September 10, 2012 at 7:16 am
Oceanographers with the Nova Southeastern University have found that some deep-sea crabs have eyes sensitive to ultraviolet light, which help them locate and sort glowing plankton, their source of food. The crabs live in the deep-sea zone, a pitch-dark area at the bottom of the ocean, typically resting on glowing, toxic corals. It is believed that the bioluminescence helps the crabs differentiate between the two; the corals glow blue-green and green, while the plankton they eat glow blue. The crabs’ sensitivity to shorter ultraviolet wavelengths may give them a form of color vision that ensures they gather food rather than poison.