Have you ever seen a freshwater jellyfish? They're just about everywhere and documented in 48 states including New York. They have a lot in common with ocean jellyfish.

We thought jellyfish were only found in salt water, but in 2016 we discovered some in Cooperstown. The above video (1:45 mark is incredible) was posted by Nathan Schoellig and Alex Krstevski.

Alex Krstevski/YouTube

It turns out they're called Craspedacusta sowerby, an invasive fresh-water bell-shaped jellyfish native to the Yangtze basin in China.

The jelly waits for suitable prey to touch a tentacle and when it does it injects poison which paralyzes the animal

They're very delicate and have numerous tentacles when fully grown. Most of the body is transparent or translucent, with a whitish or greenish tinge. Wikipedia reports prey is caught with their stinging tentacles. The jelly waits for suitable prey to touch a tentacle and when it does it injects poison which paralyzes the animal, and the tentacle itself coils around the prey. However, these cnidocytes cells are used for paralyzing very tiny prey and have not been proven to have the capacity to pierce human skin.

This map shows how common jellyfish are on the East Coast.

nas.er.usgs.gov

Since writing the story, we've been on the lookout for the freshwater jellyfish but haven't seen any. They're tough to see because they're almost 100% water and not very big. NYUp.com says they're about the size of a penny, and this is the best time to spot them when the water is warm, and their food is plentiful.


Bonus Video: