Freshwater jellyfish: Enjoying the medusa stage of nearby jellyfish and the wonder of what and why

COAL CITY, Ill.—Two years ago, Kyle Gabehart found freshwater jellyfish at the Coal City Area Club.

“Definitely thought I was hallucinating the first time I saw them,” he said. “It became a running joke with the older members, `Did you get your jellyfish yet, Kyle?’ “

Last year, Gabehart did not see any. But, in mid-August this summer, he emailed, “The jellyfish made it to the medusa stage, if you want to come down and see them. A friend took a picture and said there were thousands visible.”

In medusa stage, they look like clear pale mini umbrellas pulsing.

I met Gabehart two days later, the afternoon his classes began (online) at Joliet Junior College, where is he is studying chemical engineering.

I followed Gabehart, an avid waterfowler, around the maze of lakes at CCAC. He dropped his camouflaged 14-foot johnboat with a 9.9hp Johnson motor into the catfish pond at CCAC from an improvised launch.

Over the years, I’ve chased enough wild stories to know there are no guarantees.

But, in the middle of the pond, Gabehart’s buddy, who goes by JC, said, “There they are.”

“Oh, thank God,” Gabehart said, echoing my exact thought.

Both of us visibly relaxed. It took a few seconds, especially for me. But, as JC pointed, I became more adept at picking out the dozens of freshwater jellyfish pulsing in the water. In a good hour, we probably saw a couple thousand.

Stunningly little is known or written about freshwater jellyfish in the United States.

When I reached out to Vic Santucci, Lake Michigan program manager for Illinois, he emailed back, “I have only observed them in two or three lakes in my career, one being Devil’s Kitchen down in the Shawnee National Forest back in the 1980s. I didn’t realize they were non-native back then and was fascinated by the sheer number of the little jellyfish in the lake.”

He suggested I find an invertebrate specialist.

Enter George Parsons, senior curator of fishes at the Shedd Aquarium, who is a self-described invertebratefile, of which he said there are many.

“So unseen, only in these events [medusa] is when people take notice, when they see them swimming,” Parsons said. “Little is known about them.”

He said the freshwater jellies are found in most of the 50 states, except Alaska and Hawaii. The prevailing thought is that they are invasives from China, but there is so little known about them that even that is under debate. The freshwater jelly in question is Craspedacusta sowerbii, also known as peach blossom fish or jellyfish.

He said they have four stages. They are always around, often attached to the underside of leaves or rocks, things that are in the water.

Parsons said the medusa stage is likely related to environmental change.

``They think they ran out of room or the water is warmer or there are water quality problems, then they form the medusa,” Parsons said. “It is often in late August. [Medusae] will be around for a week or so, sometimes a little longer. They are only around for a couple weeks.”

When I asked what their place is in the ecosystem, he said they do provide food for some animals.

“Stingers are so weak and small that humans don’t have to worry about being stung,” he added.

Gabehart has a scientist’s interest in the jellyfish, He is hoping to do a research project on the jellyfish for an honor society.

“I think that [catfish stockings] might have been how they came in or on the feet of waterfowl,” he said.

Gabehart ponders such things as, “How long are they in the medusa stage?” “Male or female or reproducing asexually?” “What are possible negative effects?”

He wonders if they were put in a tank, if their life cycle could be studied.

Gabehart put his hand in and managed to catch a couple.

“Weird how they stay together,” he said. “They must have some way of communicating to the others.”

He shook some aquatic vegetation and several flared free. They went back to the plant. “How do they know?” he wondered.

Dale Bowman

He inspired me to catch one in my hand. JC wondered if they survived that, but we watched the released ones pulse off.

“[Screw] it, for the sake of science,” said Gabehart, who then dipped his green Gatorade thermos into the water and collected several jellyfish.

It was time.

“They are a cool critter,” Parsons said. “I think all jellyfish are cool, but it is a wonder they are found around here.”

Dale Bowman