US Navy sailor Daniel Hunt, home on leave in Harrisburg, was fishing from a boat on Labor Day when an object in the deep water next to his boat caught his eye.
"I looked down in the water and there it was, about the size of a quarter, pulsating in the water the way jellyfish do," said Hunt.
"It" was a freshwater jellyfish.
According to the U.S. Geological Survey the jellyfish or hydrozoan is indigenous to the Yangtze River valley in China. It hitchhiked to London along with water lily plants in 1880 or earlier and then made its way to Philadelphia sometime before a scientific paper identified it in 1928. Except in colder states, it has been found commonly in fresh water throughout the United States since then. The USGS believes the introduction of talapia brought them here.
It is most often found in slow moving or stagnant water. There are videos of jellyfish shared over Internet purportedly filmed at Mermet Springs in Massac County.
Polyps such as this survive the winter months by contracting into resting bodies or mulitcellular balls and then these podocysts grow into active form when conditions are favorable, according to the USGS.
Conditions Monday were most favorable with air temperatures in the 90 degree range and water somewhat cooler.
The USGS says on its website that the jellyfish is not considered dangerous to humans. It's stingers are too small to penetrate human skin. It isn't a man-o-war.
The strip-pit where Hunt saw the Craspedacusta sowerby is nicknamed "Blue Hole" and is a productive fishing hole left behind by coal mining companies that worked the land between Harrisburg and Creal Springs in the 1940s and later said Jerry Hunt, Daniel's father.
"It's 45 deep and the water changes color due to weather conditions. Sometimes it's very blue, not green like today," he said.
"I have caught 30 pound flat-head catfish in this pit.
"There are extremely large fish in here. There are river shad, dogfish and huge carp. There is no stream leading out of it or into it."