James Grazio, a Great Lakes biologist with the Department of Environmental Protection, never expected to encounter the animal he’d been hoping to see for the better part of his career.

On July 15, while out on Lake Erie near Presque Isle with DEP summer intern Ray Walter collecting water samples, Grazio finally spotted it — the only known species of freshwater jellyfish.

When Walter pointed out the jellyfish, Grazio was elated.

“It really made my day,” Grazio said. “I was super excited.”

The jellyfish are a non-native species from the Yangtze River Basin in China, he said.

For the last 10 years, they’ve been distributed around the world to every continent except for Antarctica.

There have been some 200 reported sightings in Pennsylvania since 1885.

This rare invertebrate, otherwise known as craspedacusta sowerbii, is exceptionally hard to see because of it’s unique life cycle.

The jellyfish begins as a polyp, which is a 1-2mm animal that lives on the bottom substrate of the body of water in which it resides.

The polyps then clone themselves, reproducing asexually.

Sometimes, the polyps create an adult medusa - which most recognize as the familiar “swimming jellyfish,” Grazio said.

Medusa are either male or female, and are only around for a short time.

As they travel in their freshwater environments, they release sperm and eggs that are fertilized and then become planula.

The planula rest at the bottom substrate of the water they were created in before becoming polyps again, and begin the cycle once more.

The jellyfish are also difficult to spot because of their size, Grazio said.

They’re about the size of a quarter.

“They do have stingers,” Grazio said. But their size prevents them from harming anything other than microscopic organisms.

Grazio and Walter collected video and photos of the jellyfish.

“We went back the nest day with the intention of collecting a specimen, but they were gone,” Grazio said.

Even still, Grazio feels lucky to have seen the jellyfish he’s been hoping to study for years.

“We were just in the right place at the right time,” Grazio said.

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