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Freshwater Jellyfish: Species of the Week

 

Picture of freshwater jellyfish

Freshwater jellyfish: don't worry, it won't sting you. Photo: OpenCage/Wikimedia Commons

 

Freshwater jellyfish have been spotted in Ohio ponds, alarming locals and surprising old timers. The local Newark Advocate quoted Frank Snelling, who has lived in the area for years, as saying, “I told him, ‘You better drink a beer. There aren’t jellyfish in Ohio.’”

freshwater species of the weekActually there are, because small freshwater jellyfish (Craspedacusta sowerbii) are native to Ohio as well as many other parts of the world. Marty Lundquist, a fisheries biologist with the Ohio Department of Natural Resources Wildlife Division, told the Advocate that his agency gets called about the small jellies every year.

Lundquist said the jellyfish like to live in ponds with good water quality, and that they usually hang out near the bottom. They prefer calm water and are also found in flooded quarries and lakes. They enter new habitats as polyps stuck to vegetation or birds, or transported in bait buckets.

The freshwater jellies do have stinging cells but they are so small that they usually don’t hurt vertebrates (the whole animal is only about 1 inch (20–25 mm) across).

The jellies live off copepods and other zooplankton, which they paralyze with their ring of 400 slender tentacles. They pull their prey into their mouth, which hangs below the translucent bell. Freshwater jellyfish may have a whitish or greenish tinge.

These small animals have been reported in many countries around the world, from Thailand to India to Brazil, and in most U.S. states and Canadian provinces.

Like many jellyfish, this species has a complex lifecycle that includes a polyp phase, a larva phase, eggs, and the most familiar, the medusa (the one that looks like a jellyfish). When conditions get tough, they can wait it out in a dormant resting phase at the bottom.

So next time you take a dip in an old quarry or swimming hole, see if you can find any one-inch freshwater jellyfish. They won’t sting you, and they’re part of a healthy ecosystem.

Learn about the golden jellyfish in Palau’s saltwater lake>> 

See amazing jellyfish photos>>

 

Picture of Craspedacusta sowerbyi freshwater jellyfish

Freshwater jellyfish prefer slow-moving, clean water and can be found all around the world. Photo: J. Michael Tracy, Wikimedia Commons

 

Brian Clark Howard covers the environment for National Geographic. He previously served as an editor for TheDailyGreen.com and E/The Environmental Magazine, and has written for TheAtlantic.com, FastCompany.com, PopularMechanics.com, Yahoo!, MSN, Miller-McCune and elsewhere. He is the co-author of six books, including Geothermal HVACGreen LightingBuild Your Own Small Wind Power System, and Rock Your Ugly Christmas Sweater.

 

Comments

  1. Robert Grove
    Acworth, Georgia
    January 5, 5:17 pm

    These 1″ jelly fish are in Allatoona Lake also. We have seen them more abundant in the stamp creek area of the lake.

  2. tory asher
    indiana
    October 14, 2013, 12:27 pm

    we were out fishing yesterday and we seen a bunch of 1″jellyfish

  3. Donna
    Fl
    June 14, 2013, 3:41 pm

    I seen millions of these in the little kanawha river in Parkersburg wv. They were not on the bottom the were from the top of the water to about 2 feet down. This was 20 years ago and no one believed me.

  4. Chandra
    qufblivYVvno
    September 24, 2012, 11:24 pm

    A tripod is esanetisl. In dark light, any amount of camera shake is ten times more disastrous to your photograph. Don’t use Flash, it will cause glare on the glass and most likely scare the fishies half to death!Like these guys have said, up the ISO/ASA film speed to 400 or above this allows for better photographs in limited light. There’s never a specific or specific setting for photography, its so dependant on available light etc so the most important thing you can do is just keep experimenting, and take a little notepad with you so you can write down what exposures you used for each shot and state what the light was like then in future, if you are in a similar situation, you can get your notes out and use it as a reference.Hope your trip is fun!

  5. Irene Klarich
    Oroville, California
    September 20, 2012, 3:03 pm

    Saw these friendly little fellas for the first time this summer in Lake Oroville, California. When we anchor the boat to fish, they come around to see what we are! Saw them in groups of 3 or 4. Never seen them before in Lake Oroville till this year. Had to look it up…glad I did!

  6. ANDRES MARTINEZ
    Massachusetts
    September 9, 2012, 10:14 pm

    I love your article. I just saw the fresh water jelly fish last Friday in a locally pound in my area, it was millions of then very happy swimming around my boat. My Science Prof. Beluzo was very happy to see then it was like he saw a 100$ bill in the water. It was a great article you wrote and amazing pictures. I am so happy to find it in my assignment research you save my life with your incredible article. Thank you..they are amazing creatures ..love them, I am going to make a painting and please let me know if you want to see it, maybe you can utilize for some illustrations or cover of your book. Than you for it!!
    Andres

    • Brian Clark Howard
      September 10, 2012, 10:24 am

      Thanks Andres! I’d love to see your painting. When you’re done, send it over.
      Best

  7. Jay
    Glendale R.I. Spring Lake
    September 4, 2012, 8:21 pm

    These Jellies have showed up in this lake. Never before. Schools of THOUSANDS especialy when sun is out. Its freaky and I hope it wont be worst next year!

  8. Ima Ryma
    September 1, 2012, 4:08 am

    Craspedecusta sowerbii,
    In the Cnidaria phylum,
    AKA hydromedusae,
    Freshwater jellyfish, in sum.
    We like to show up unannounced,
    Catching a ride on what we can,
    Till in some water we get bounced.
    Tiz not a real well thought out plan.
    The locals kinda get freaked out
    When they first get a peek at us,
    ‘Fraid they’re gonna get stung, no doubt -
    But just if we can eat the cuss.

    We’re only about one inch big,
    So don’t do the human lunch gig.