Freshwater Jellyfish

[LKunze]

Last update: September 28, 2006 – 6:07 PM

Jellyfish appear in Minnesota lakes
Tiny freshwater jellyfish, usually rarely seen in the area, have been making appearances in northeastern Minnesota lakes this year -- including Little Sturgeon Lake north of Hibbing and Dodo Lake near Duluth.
Associated Press, Associated Press

DULUTH, Minn. — Tiny freshwater jellyfish, usually rarely seen in the area, have been making appearances in northeastern Minnesota lakes this year.

In recent weeks, there have been reported jellyfish sightings at a few area lakes, including Little Sturgeon Lake north of Hibbing and Dodo Lake near Duluth.

These jellyfish spend most of their lives as underwater polyps that live on or near lake bottoms. On seldom occasion, they develop into dime- to quarter-sized jellyfish that can be seen floating and pulsing near the surface. The "blooms" last only a few days with most sightings occurring in August and September.

"It's an odd little critter that's in some of our lakes that we don't know a whole lot about," said Gary Montz, aquatic biologist for the Minnesota Department of Natural Resources division of ecological services. "They sometimes don't appear for years, then suddenly there's an explosion of them in a particular lake. It only lasts for a few days, though, so a lot of people have never seen one."

Dr. Terry Peard, professor of biology at Indiana University, said there could me more jellyfish sightings now as northern lakes get warmer earlier in the year and stay warmer later.

Freshwater jellyfish are too small to sting people as larger saltwater jellyfish can.