Sea life color codes food to evade danger_美文

Sea life color codes food to evade danger

For the second study, researchers collected species and brought them to the surface. Frank placed tiny electrodes on their eyes, and made a curious finding.

“That there are several species of deep sea crab that have both a blue and an ultraviolet visual pigment,” says Nova Southeastern University biologist Tamara Frank, who led the study.

Most creatures in the deep sea have evolved to detect only blue light, not the shorter ultraviolet waves that don’t penetrate to the sea floor.

Johnsen, a co-author of this study, says crab behavior provided a clue about why they could see both.

“And as they touched these plankton and feed on them, those glow blue. But as they touch the coral they are standing on, that glows green.”

“What we hypothesize is that they are picking off the blue stuff, which they like to eat," says Frank, "and when the blue stuff hits the green stuff with that ultraviolet visual pigment, they can tell the difference between the blue and the green and therefore pick off what they like to eat versus what they don’t like to eat.”

Johnsen adds, “And so what our guess is - but we are not certain of this yet - is that they are actually using their color vision. In other words, blue comes from the water, blue is tasty. Green is what I am standing on. I don’t want that. It’s toxic.”

Understanding how deep sea animals see has led to a greater understanding of deep space. An orbiting x-ray telescope was inspired by the wide-angle vision of lobsters.