ASSATEAGUE ISLAND, Md. (WJZ) — If you’ve found circular, jellyfish-like creatures along the beach on Assateague Island — they are actually not jellyfish. They are called salps.

According to the Assateague Island National Seashore‘s Facebook page, salps are “free-swimming planktonic tunicates that are likely on the beach due to offshore phytoplankton blooms.”

The salps will reproduce by cloning themselves in long chains that look like clear blobs.

They were seen along the beaches of Assateague Island over the holiday weekend.

“As they pump to filter food out of the water they also move themselves forward with jet propulsion, making them one of the best vacuum cleaners of the ocean” national park officials posted.