Melbourne, Australia, September 25, 2008--The ghostly silhouette of a marine biologist is seen during maintenance of a tank full of moon jellyfish at the Melbourne Aquarium.

Moon jellies are commonly found in warm and tropical coastal waters of the Atlantic, Pacific, and Indian Oceans.

The jellies are part of the museum's recently opened Unimaginable Floating Objects (UFOs) exhibit. Other jellies on display include blue blubbers, combs, and the Irukandji, which has a potent stinger.

--John Roach

—Photograph by Mick Tsikas/Reuters