Gocke, Judith P.

In the ocean, lighting varies with habitat; the eye's spectral sensitivity must vary with visual ecology. Green turtles are the only sea turtle whose spectral sensitivity has been studied. Loggerheads and leatherbacks see visible light between 340 and 700 nm. However, the wavelengths detected with the greatest sensitivity by both species are those best transmitted at the specific depths where food, mates and predators are likely to be encountered. Both species have trichromatic vision, but the species differ in the concentration and peak sensitivity of each visual pigment resulting in either a broadly tuned (loggerhead) or finely tuned (leatherback) spectral sensitivity. Spectral sensitivity of leatherbacks overlaps both bioluminescence of prey, and light available in clear, deep, oceanic waters.