Freshwater Jellyfish

Type: Nontidal
Region: Central
Location: Liberty Reservoir

I have been fishing Liberty Reservoir every weekend since about 1986. Today I saw something I had never seen before. I saw hundreds of jellyfish from Oakland Point to Bollinger Mill. Some where the size of a quarter but most were smaller. I brought one home and put it in an aquarium.

DNR's response By Biologist Susan Rivers: Yes, there is such a thing as a freshwater jellyfish. Jellyfish usually have two stages to the life cycle � the hydra and the medusa (jellyfish stage). The freshwater jellyfish, Craspedacusta sowerbyi, is unusual because it can spend many years showing just the hydra stage. We aren�t sure what triggers the appearance of the jellyfish stage, but it is being seen more and more in freshwater ponds and lakes across the state. The unfortunate part is that they occur so infrequently that it makes it difficult to get a handle on their biology and ecology. Feeding with plankton everyday appears to be a critical issue. The degree of plankton blooms in ponds may be a key to their appearance.