08/13/2025
Non-native but not invasive
Ohio History Hunter
Medusas Stones LLC
Mark Johnson
Ohio Rockhounding Fossils Artifacts and Rock Tumbling
Lake Erie Fluorescent Mineral Hunters Group
Yesterday, we posted about a freshwater jellyfish spotted off Stone Lab's docks. After some additional research from our team, we misidentified this species as invasive. We wanted to make a post to correct this mistake in addition to editing the post. We apologize for the confusion this might have caused.
This freshwater jellyfish is non-native but not invasive. All invasive species are non-native, but not every non-native is invasive.
This freshwater jellyfish (Craspedacusta sowerbyi) are native to China’s Yangtze River basin, so are considered non-native. They are not harmful to native species here, so they are not invasive.
The size of the jellyfish here measure at 3/4 inch in diameter (range in size from 5-25mm). They sting prey, but their stingers are too small to pe*****te human skin!
There have been multiple sightings of them around the islands over the weekend and at Erie, PA last week.
Photo Credit: Stone Lab Tech Kelly Peterson.
