MAHASKA COUNTY, Iowa — Oskaloosa High School freshman Oscar Schiferl was fishing at Russell Wildlife Area in Mahaska County this weekend when he discovered an oddity for the state of Iowa, the Oskaloosa Community School District said.
While he had his sights set on catching a bass with his dad, he instead found a freshwater jellyfish native to Asia, known scientifically as Craspedacusta sowerbii.
“I saw the jellyfish swimming in the water, and my dad didn’t believe me at first, so I caught one to show him. He was like, ‘That’s actually a jellyfish,’” Schiferl recalled.
According to the Iowa DNR (Department of Natural Resources), the occasion marked the second time seeing freshwater jellyfish in the state this fall with the first time occurring within the week at Lake Panorama in Guthrie County.
After his initial discovery, Schiferl soon found abundantly more of the intriguing creatures.
“I saw a whole lot more of them out there,” Schiferl said. “I caught about 20, but my dad wouldn’t let me keep more than two.”
The question of what the jellyfish could mean to Iowa's ecosystem was addressed by Kim Bogenschutz, Aquatic Invasive Species Coordinator for the Iowa DNR.
“These jellyfish probably arrived here unintentionally, likely through aquariums or aquatic plants,” she said. “While they don’t seem to have invasive qualities or pose a major threat to native species, it’s crucial to prevent further spread.”
Although these jellyfish are considered relatively harmless as they tend to not outcompete native species and can't hurt humans, Bogenschutz emphasized what nonnative species can do, saying, "The message is simple: don’t dump aquariums into lakes or ponds. Even small actions like that can introduce species that don’t belong and disrupt ecosystems.”
As temperatures continue to dip as Iowa enters its colder months, she also added that the jellyfish may not be around for much longer.
“These jellyfish are sensitive to temperature changes,” Bogenschutz explained. “As the water cools, they’ll likely disappear back into their resting stages. But it’s moments like these, when students find something unexpected, that remind us how important it is to stay curious and observant.”
After it all, Schiferl says he was just excited to share his discovery with his classmates and teachers by taking one of the jellyfish to school in a mason jar.
“I don’t really need the fame or anything,” he said with a laugh. “I just thought it was cool and wanted to show people.”
The Oskaloosa School District has praised Schiferl for his curiosity and how he raised awareness about invasive species, and it says students have become increasingly intrigued with local wildlife, even saying they want to go explore Russell Wildlife Area in hopes of finding more jellyfish.
“I’m just glad I found them,” Schiferl said. “It’s not every day you catch jellyfish in Iowa.”
