Elegant jelly

At the Aquarium

"No one knew the elegant jelly fluoresced until we tested them," says Senior Aquarist Wyatt Patry. After obtaining polyps from Ocean Park Hong Kong in China, Wyatt collaborated with Steve Haddock from the Monterey Bay Aquarium Research Institute (MBARI) and discovered how to illuminate the jelly and display this species for the first time at the Aquarium.

So how do you make an elegant jelly glow? "You have to use a very specific wavelength of light. We found the right type of bulb that gives them the bright florescence you see," Wyatt says. Using a particular type of blue light and a yellow filter in front of the tank, they're able to excite proteins inside the jelly that it creates. "The jellies make the proteins and we illuminate them to create a beautiful display. They glow beautiful green-blue colors."

Fluorescence is a completely new way of presenting jellies at aquariums. "We have a fluorescence Kreisel tank that's completely new—no one's ever done that," Wyatt says of exhibiting the elegant jelly. The Aquarium uses a standard Kreisel, or round tank that helps keep the jellies suspended, and "dresses it up" so that viewers can't see the filter or blue lights, Wyatt explains. "You see these beautiful, green, glowing jellies—all we're doing is highlighting them for our guests."

Natural History

Little is known about the elegant jelly. So little, in fact, that it hasn't been described yet and doesn't have a species name. In raising them in captivity for display at the Aquarium, our aquarists found the species to be extremely prolific because the jelly produces many medusae at once.

The elegant jelly's entire bell illuminates bright green when exposed to blue light. But it doesn't produce light—it contains fluorescent molecules that are excited, or glow, when lit by certain wavelengths, much like a black-light poster. What makes this jelly glow in the wild? Scientists still aren't sure, but one guess is the light from a full moon near the ocean's surface. Why animals fluoresce is also a mystery—scientists think it might help some jellies startle potential predators or attract prey.


Jelly populations naturally ebb and flow. Scientists are now wondering whether human impacts like overfishing, pollution and possibly climate changes might affect jelly populations also.

Cool Facts

Fluorescence is brighter in younger elegant jellies than in adults. To keep their fluorescence as adults later in life, elegant jellies are thought to prey upon and eat other jellies that have it.

The fluorescent proteins from jellies are used in the biomedical field for many different research studies, including cancer and Alzheimer's disease.