Invertebrates
Freshwater Jellyfish
Craspedacusta sowerbii · also called peach blossom jellyfish
On a warm August day, hundreds of coin-sized freshwater jellyfish pulse through the green water of a flooded quarry, appearing as if from nowhere.
Overview
The freshwater jellyfish, Craspedacusta sowerbii, is a tiny, harmless jellyfish native to China that has spread to lakes, quarries, and reservoirs on every continent except Antarctica. Its sudden blooms, hidden polyp stage, and surprising habitat make it one of the strangest animals to turn up in an English pond.
A jellyfish that lives in a lake
Most jellyfish are marine, but the freshwater jellyfish has made a home in still inland waters, hiding as a polyp for most of the year and budding off jellyfish only when summer water is warm.
Status
Not Evaluated, but widespread.
Freshwater Jellyfish: common questions
Are there jellyfish in fresh water?
Yes, the freshwater jellyfish is a tiny, coin-sized jellyfish that lives in lakes, quarries, and reservoirs around the world.
Can the freshwater jellyfish sting?
Its stinging cells are too weak to affect humans, so it is harmless to swimmers.
Why do they appear suddenly?
They bud off from a tiny polyp, and blooms appear in warm summer water and then disappear again.
Where did the freshwater jellyfish come from?
It is native to the Yangtze River region of China, and was first found outside Asia in a London lily pond in 1880.