Wait… Indiana Has Jellyfish?
When you think of jellyfish, your mind probably drifts to tropical oceans, salty sea breezes, and maybe a beach day gone slightly wrong. But what if we told you that jellyfish are quietly pulsing their way through freshwater lakes and ponds right here in Indiana?
That’s right! Meet Craspedacusta sowerbyi, Indiana’s most unexpected aquatic resident. These pint-sized freshwater jellyfish have been spotted in lakes, reservoirs, and even quiet fishing ponds across the state. They're not native to North America, but they’ve been around since at least the early 1900s and seem to be making themselves at home in Hoosier waters.
So… What Are They?
These freshwater jellyfish are tiny. We’re talking about the size of a quarter, maybe a silver dollar if they’re really showing off. They're translucent, a bit ghostly, and float gently through the water like something out of a nature documentary narrated by David Attenborough (if he ever made a stop in Brown County).
Despite their delicate appearance and fancy Latin name, they’re not dangerous. Their tentacles do have stinging cells, but they’re too weak to harm humans. So you won’t be dodging jellyfish while swimming in Lake Monroe anytime soon.
Where Do They Live?
Freshwater jellyfish love calm, still water—ponds, lakes, and slow-moving rivers are their ideal spots. They tend to show up in late summer when the water is warm, but even then, sightings are rare and often fleeting. One day they’re there, the next they’ve vanished like little aquatic ghosts.
They don’t thrive year-round in Indiana’s colder waters. Instead, they spend most of their lives in a microscopic, non-jellyfish form (kind of like plant roots underwater). When the conditions are just right with warm temps and still water, they bloom into those jellyfish-like medusas we occasionally see.
How Did They Get Here?
Believe it or not, these jellyfish are world travelers. They likely hitched rides in aquatic plants, ballast water, or even aquarium supplies. Once introduced to a new body of water, they quietly set up shop, waiting for their moment to shine.
Why Should We Care?
Well, aside from being a fun fact to bust out at your next summer cookout, freshwater jellyfish are a gentle reminder of how surprisingly diverse Indiana’s ecosystems are. From salamanders to sandhill cranes, and now jellyfish, our natural spaces are full of surprises.
Plus, spotting one is a bit like finding a four-leaf clover. They’re unusual, beautiful, and worthy of a selfie all at the same time.
Next time you're out kayaking or casting a line on an Indiana lake, keep an eye out for these tiny drifters. They won’t sting, they won’t bite, and they certainly won’t ruin your day. In fact, they might just make it a little more magical.
