Thursday, September 21, 2006

Indiana Jellyfish

The Indiana University newspaper has an article about jellyfish that live in fresh water lakes around here. That's pretty fun - it's not something that I usually think about - jellyfish in Indiana. It just goes to show you how universal they are. :)

Jelly fish Season

The white cross of the jellyfish distinguished its body against the dark background of Yellowwood Lake in Brown County. The rest of its transparent structure appeared as it slowly glided through the water. As stealthily as it surfaced, it sunk back into the darkness below the boat.

No one is quite sure when these elegant creatures arrived in local lakes, but their existence speaks to Indiana's impressive biodiversity and begs the question: Why would an animal so closely associated with marine environments annually show up hundreds of miles away from the nearest ocean?

....Jellyfish are most often spotted in August and September when the water is warm enough to allow them to grow....

People see the more recognizable medusa stage, or reproductive stage, of the jellyfish life cycle, said Terry Peard, professor of biology at Indiana University of Pennsylvania, who studies freshwater jellyfish. Most of the rest of the year is spent attached to the underside of a log as a polyp, a tiny speck of an animal barely 1 millimeter in height.

Peard's research shows that these jellyfish are heartier -- and more adaptable -- than their delicate bodies, composed of more than 99 percent water, might suggest.

"We have collected jellies from bodies of water that run the gamut from pristine to various levels of pollution"...
Peard said he has found that jellyfish in the medusa form might migrate from site to site in boats, in bait buckets, by flooding or via underground aquifers connecting bodies of water....

"Most people are unaware they can find them as close to home as Indiana," (Cotten) said. 

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