"Pink Meanie" Pictures: New Jellyfish Attacks Other Jellies

A Taste for Its Own Kind

Photograph courtesy Mary Elizabeth Miller, Dauphin Island Sea Lab

Captured off the Florida Keys, a Drymonema larsoni jellyfish—aka a pink meanie—swims in a lab tank.

According to the new analyses, this Gulf of Mexico Drymonema species is genetically distinct from its Mediterranean cousin, D. dalmatinum.

Regardless of where they live, all Drymonema species have an appetite for moon jellyfish, which the Drymonema feed on almost exclusively as adults.

"They just spread their tentacles out, and as soon as they come into contact with a moon jellyfish, they get more tentacles around them and pull them in," the Dauphin Island Sea Lab's Bayha explained.

Adult Drymonema do the majority of their digestion using specialized "oral arms" that dangle alongside their tentacles. The oral arms exude digestive juices, which break down the prey.

(Related: "New Jellyfish Species Found.")

Published January 24, 2011

Gulf War

Photograph courtesy Don Demaria

A relatively small Drymonema larsoni jellyfish attacks a much larger moon jellyfish in the Gulf of Mexico.

Drymonema can vary greatly in size. Some, like the one pictured here, are only a few inches across, while others can grow to several feet in diameter.

"They just keep growing, but most jellyfish live only a year," Bayha explained. "They'll breed and then they'll kind of stop eating and senesce, shrivel up, and die."

(Also see "'Immortal' Jellyfish Swarm World's Oceans.")

Published January 24, 2011

Moon Shot

Photograph courtesy Mary Elizabeth Miller, Dauphin Island Sea Lab

Swimming in a tank, a Drymonema larsoni jellyfish captured off Alabama ropes in a bulbous moon jellyfish.

While Drymonema jellyfish feed mainly on other jellyfish, the stinging cells in their tentacles are potent enough to be felt by humans.

"They're really bad stingers," Bayha said. "The more tentacles come into contact with you, the worse the sting is going to be. And these guys have hundreds and hundreds of tentacles."

(Pictures: "Alien" Jellyfish Found in Arctic Deep.)

Published January 24, 2011

The Big Pink

Still from video courtesy Monty Graham, Dauphin Island Sea Lab

An adult pink meanie jellyfish measuring nearly three feet (one meter) wide searches the Gulf of Mexico for other jellyfish to eat.

Larger Drymonema can ensnare multiple moon jellyfish at once—one had been found with 34 moon jellyfish in its tentacles.

Since many jellyfish look very similar, past researchers assumed that there are very few jellyfish species. But UC Merced's Michael Dawson has revealed many cryptic jellyfish—jellies that look the same but are actually separate species.

While the discovery that a single global species might actually be multiple species may seem trivial, it can become important when studying jellyfish ecology, since different species might behave differently.

"It changes the way in which we can study these guys and how they interact with humans and the marine environment," Bayha said. "And they're being recognized more and more as a major pest around the world."

(Also see: "Giant Jellyfish Pictures: Japan's Nomura Invasion.")

Published January 24, 2011