Photo: Glow-in-the-dark starfish

Glow-in-the-dark starfish that live in deep waters off Greenland use their self-produced light to find their way through the dark—and to attract mates. Anders Garm from the University of Copenhagen, the lead author of a study recently published in The Royal Society’s Biological Sciences journal, has called this use of lights “an advanced form of communication, which was previously unknown in animals like starfish.” The study looked at 13 species of starfish from Greenland waters, covering a range of depths from shallow waters to the deep sea below 1,000 metres. This starfish, Novodinia Americana, can see as well as starfish in shallow waters. Its eyes are composed of small units that produce an image of a few hundred pixels. The body of the starfish also emits light. (PHOTO BY OLA ZIMINA, GREENLAND INSTITUTE OF NATURAL RESOURCES)