Glow-in-the-dark corals light up the deep sea

A team of MBARI researchers filmed the dazzling light displays (known as bioluminescence) from various deep octocorals—soft corals, sea pens, and gorgonians—in their habitat for the first time. Working with our remotely operated vehicle (ROV) pilots, the scientists were able to equip the ROV Doc Ricketts with an extremely light-sensitive camera. Many bioluminescent species only glow when disturbed, so the researchers filmed the animals while gently touching them with the ROV's manipulator arm or a soft paintbrush. They found that several of the most common deep-sea corals can create their own light, including a number of groups not previously known to luminesce. Before this study, biologists already knew that some octocorals exhibited bioluminescence. But this research suggests that octocorals evolved the ability to glow very early in their evolutionary history.