30-07-2025
A jellyfish at Presque Isle? What you should know about this freshwater species
First it was an alligator in Lake Erie, now a jellyfish-like creature has been spotted in Presque Isle.
On July 29, according to a Facebook post from the Pennsylvania Department of Environmental Protection, DEP intern Ray Walter spotted what was described as an incredibly rare organism off the dock at Marina Lake within Presque Isle Bay.
The organism was identified as a "Craspedacusta Sowerbii," or in laymen's terms a freshwater jellyfish.
The DEP stated on its Facebook page that the freshwater jellyfish is hard to find and most of the time doesn't make a surface appearance as it is often found stuck to the bottom of a polyp.
Occasionally this organism will form into the shape of a jellyfish.
Here's more on what you need to know about the Craspedacusta Sowerbii.
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What is a Craspedacusta Sowerbii?
The Craspedacusta Sowerbii is a freshwater hydrozoan jellyfish, according to the United States Geological Survey website. It's the only known species of freshwater jellyfish found in North America.
What does a Craspedacusta Sowerbii look like?
Often the size of a penny, the Craspedacusta Sowerbii can measure from 5 to 22 millimeters.
According to the Craspedacusta Sowerbii shares many similar traits and characteristics of a jellyfish.
It can be a white or green colored creature with 99% of its body made of water. The organism lacks a skeleton and contains no organs for breathing.
It can have anywhere between three and seven string-like tentacles which helps it capture food and remain safe against predators.
At the end of the tentacles, freshwater jellyfish have eyespots which are used to detect light and dark to also assist in escaping predators and finding food.
For movement, the Craspedacusta Sowerbii can move in any direction by pulsating contractions.
Where are Craspedacusta Sowerbii typically found?
The Craspedacusta Sowerbii can be found in a variety of freshwater environments including lakes, reservoirs, man-made impoundments, rock quarries, algae-filled ponds and even rivers.
They often live in shallow water to conserve energy. The organism is often spotted in the summer and fall months when water temperatures warm up.
Can I get stung by a freshwater jellyfish?
Although the Craspedacusta Sowerbii possess stinging cells, they are unable to penetrate human skin. Therefore, the freshwater jellyfish cannot give you a painful sting unlike other jellyfish.
What does a freshwater jellyfish eat?
states that a freshwater jellyfish eats zooplankton. They use their tentacles to sting the prey to immobilize said prey before eating it
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What do I do if I spot a freshwater jellyfish?
If you are around the Presque Isle area and you happen to spot a freshwater jellyfish, it is not cause for alarm. You can call the Department of Conservation and Natural Resources to report them so they can track and keep record of the organism.
Contact Nicholas Sorensen at Nsorensen@
(This story has been updated to add new information and to correct an inaccuracy.)
This article originally appeared on Erie Times-News: What to know about freshwater jellyfish spotted at Presque Isle
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