"It was totally unexpected," said chief scientist Tammy Frank of the UV-seeing crab.
To discover the crab's secret, it had to be carefully brought up from the depths in a cold, dark container. The depressurization was not so much an issue because crabs have no swim bladders, and so are not sensitive to pressure changes as are many fish.
Once onboard, it took some very careful laboratory work to find out which wavelengths of light the crab's eyes responded to.
"The problem is that most of their eyes are so sensitive that most of our instruments blind them," said ocean scientist Edith Widder, of Ocean Research and Conservation Associates.
Between seeing which animals fluoresce and bioluminesce, and which see in different colors, researchers are beginning to get an inkling of a whole ecological system of lighting going on all over the planet's oceans — in the dark. Piecing together exactly who is seeing whom and in what color and with what sorts of strange eyes is the "ultimate goal" of their researcher, said Mike Matz of Harbor Branch.
Unlike bright white lights used on most submersible vehicles or nets used to capture deep sea organisms, the Eye-in-the-Sea is designed not to disturb creatures, and in fact attract them.
