September 1, 2009

New Jellyfish Species Discovered In Arctic Waters

Scientists have published new descriptions of a range of jelly-like animals that were originally filmed and photographed during a series of dives in the deep oceans of the Arctic in 2005, BBC News reported.

Experts say one of the types of jellyfish discovered in the Arctic, which is isolated from much of the water elsewhere on the globe, is completely new to science.

The Canadian Basin is one area of the Arctic that is cut off by deep-sea ridges that isolate any species there from other deep-water animals.

The U.S. National Oceanic and Atmospheric Administration's Office of Ocean Exploration and Research funded an international team of scientists to explore a series of deep-sea dives using a remote operated vehicle (ROV) in 2005.

The explorers have now published details of what they found in the journal Deep Sea Research Part II.

Biologist Dr. Kevin Raskoff of Monterey Peninsula College in California is a leading member of the dive team. He acknowledged that they discovered many surprises during their plunges in the icy cold depths.

"One thing was just how many different jellies there were, and the sizes of their populations," he said.

He noted that some of the jellyfish were somewhat well known from other oceans, but had not previously been found in the Arctic.

"That caused us to rethink our ideas about what the typical habitat would be for the species. We also discovered a number of new species that had not been found before," he added.

The team conducted a series of deep dives where the ROV filmed over 50 different types of gelatinous or jelly-like animal. Medusae, a particular type of jellyfish that tend to be bell or disc shaped, made up the majority of types recorded.

Ctenophores, an unusual group that can look like jellyfish, but are not able to sting, Siphonophores, which are colonies of smaller animals living together in a structure that looks like a single, larger animal, and Larvaceans, plankton-like creatures unrelated to jellyfish, were among the others that were filmed.

Researchers said two species of Medusae dominated most locations visited by the ROV.

One was Sminthea Arctica, which lives at depths ranging from 328 feet to 6,800 feet, and has been documented before by scientific expeditions.

But the other species was a whole new find for science.

Raskoff said the single most interesting discovery was a new species of a small blue jellyfish, from a group called the Narcomedusae.

"This group has several interesting features that set them apart from typical jellyfish, such as the fact that they hold their tentacles over their bell as they swim," he said.

Raskoff noted that while most jellyfish let their tentacles drift in the water behind them, the new species holds its tentacles out in front, perhaps enabling it to better catch its food.

This new species will even be classified within its own genus and will be formally described later this year. Raskoff added it was also the third most common jellyfish found on the dive.

"It's surprising when you think about the fact that even the most common species in the area can be a totally new and unexpected species," he said.

The explorers also recorded an Aulacoctena, a type of ctenophore, which they called one of the most spectacular examples of its kind. Although it is under a foot long, its tentacles can grip almost anything underwater and very little is known about its lifestyle.

But the researchers said one of the specimens collected by the ROV ejected its stomach contents, revealing it might have fed on a bright orange animal. They suspect it feeds on bright orange worms that also live in the Arctic deep, and it gets it color from its prey.

The team hopes to find out more about how these creatures interact with their environment, and how they influence or underpin the ecology of the deep ocean in which they make their habitat.

The scientists also plan to explore other little-visited regions of the deep Arctic ocean and the Aleutian trench off the coast of Alaska.

"You don't have to go too far to find interesting areas to study, you just have to dive deep," Raskoff said.


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