Look at a starfish in a tidal pool and you might think: Ah, there’s one of those pretty, multi-armed sea worms that crawl around and don’t do much. But look deeper and your views might change.
To the surprise of scientists, hundreds of feet below the ocean’s surface, some starfish make their own light, and they have a teeny eye on the tip of each arm.
They collected starfish from Arctic waters off Greenland’s coast to determine which species had eyes, and for those that did, how well they could see. The researchers found that some starfish are far more biologically complex than previously thought, after looking at the structures of their eyes, their behavior in a simulated environment, whether they glowed in the dark and what tasks in the wild would make eyesight useful.