I had no idea freshwater jellyfish even existed until we saw a swarm of them while kayaking. I took a short video with my digital camera and managed to capture a few decent shots. They were about the size of a quarter and there were literally thousands of them. I did an online search and discovered that they were freshwater medusa jellyfish, a non-native species currently found in pretty much every state. They have the same stinging barbs as saltwater jellyfish but are apparently too small to sting human beings-definitely good news there! They're easiest to spot in late August/early September, so keep an eye out for them if you're going on the water.
Science Buzz-Freshwater Jellyfish