What’s that in the water? Freshwater jellyfish

As anglers, swimmers and other water recreation fans flock to Michigan lakes and streams this summer, some may catch a glimpse of a common, though rarely seen invertebrate known as the freshwater jellyfish. Don’t be concerned though — these jellyfish are not harmful to humans and are believed to have negligible adverse effects on the aquatic environment.
Freshwater jellyfish (Craspedacusta sowerbyi) are related to the various marine species of jellyfish, but in essence are not true jellyfish since they have a membrane called a velum that the marine species do not. Despite this difference, the appearance and movement of freshwater jellyfish mimic those of a true jellyfish. They are not native to Michigan or even North America and are believed to be native to China and Asia. However, this species has been found throughout most of North America for well over a century and is considered to be a nonharmful member of our aquatic communities, and certainly an intriguing one. Read more