If you're lucky enough to see this view through the lens of your diving mask, you must be snorkeling in Jellyfish Lake on the island of Eil Malk in the Pacific island nation of Palau. Golden jellyfish are a subspecies unique to this small lake, on this small island—they're found nowhere else on the planet. Millions of teacup-sized golden jellies inhabit the lake, following the sunlight that nourishes them. Symbiotic algae live inside the jellyfish and provide their hosts with energy as a byproduct of photosynthesis. The more sun the jellies get, the more energy they derive from their hitchhikers. The jellies start the day at the east end of the lake and drift westward until dusk, following the arc of the sun.