Oct 16, 2009By P.J. REILLY, Staff Writer
Robert McLane thought the woman canoeing near him Sunday was joking when she yelled out that she was looking at jellyfish in the Lancaster Township quarry.
"I laughed," said McLane, 71, of Millersville. "I figured she was looking at fish eggs or something."
But when McLane boated over to investigate, he found himself surrounded by thousands of pulsing, translucent creatures.
"They were all over the place," he said. "I've never seen anything like it."
McLane cut the top off a plastic water bottle, dunked the container under the surface and came up with a freshwater jellyfish captured inside.
"It's really small, but it looks just like a jellyfish you'd see in the ocean," he said.
Having never seen or heard about freshwater jellyfish, McLane contacted this newspaper to report his unusual catch, then returned the creature to the quarry Tuesday afternoon.
It turns out, freshwater jellyfish — or craspedacusta sowerbyi, as they are known to scientists — are not uncommon, yet they are not often seen.
"Mostly that's because they are hard to see and people aren't looking for them," Larry Reinking, a Millersville University biology professor, said.
Coincidentally, several freshwater jellyfish showed up in August in a Millersville University pond that's used for research.
The last time Reinking saw them in that pond was in 2004.
He and junior biology major Ian Miller seized the opportunity afforded by the jellyfish's appearance in the campus pond to launch a research project.
"We don't really know a whole lot about them," Reinking said. "This is kind of an opportunistic study."
According to Reinking, scientists believe there is only one species of freshwater jellyfish found in North America.
They are not sure how the animals — they are not actually fish — get into ponds, quarries and other isolated bodies of water, he said, although they believe waterfowl possibly carry them from one place to another.
The jellyfish exist in two forms. In the "medusa" stage, they look like the jellyfish you'd see in the ocean, although they are mostly clear and are no larger than a quarter.
In that stage, the jellyfish emit eggs and sperm, which meet and create larvae that attach to flat surfaces and eventually turn into stalk-like polyps.
Those polyps reproduce, creating offspring that take the form of jellyfish, Reinking said.
Why the jellyfish seem to appear in large numbers one year and then disappear for several years, Reinking said, is a mystery.
The study on which Miller is working hopefully will shed light on how deep and in what concentrations the polyps like to establish themselves.
"It's some very basic information that we just don't have," Reinking said.
Terry Peard is a retired biology professor from Indiana University of Pennsylvania who now is working as an adjunct professor at Millersville. He maintains the Web site freshwaterjellyfish.org, which provides information about the jellyfish and tracks their appearances all over the world.
According to the site, the jellyfish have been documented at one time or another since 1990 in 10 bodies of water in Lancaster County, including Octoraro Reservoir, Muddy Run Recreation Lake and Bainbridge Quarry.
The Web site also states that freshwater jellyfish are capable of stinging people.
"However, we have no hard evidence that these organisms can penetrate human skin — though some have claimed otherwise," the Web site states.
http://articles.lancasteronline.com/local/4/243500
(Submitted by Andrew D Gable)
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