How to remove Chaetogaster limnaei limnaei

Chaetogaster limnaei limnaei is a species of a small freshwater oligochaete that is an episymbiont on freshwater snails. It is considered to be ubiquitous.

I have collected one Lymnaea stagnalis and few Stagnicola sp. species in the outdoor shop of various plants including wetland plants and freshwater plants. I noticed tiny white worms on snails later when I put snails into my aquaria.

These worms are predators of various aquatic animals including medically important trematodes. Trematodes parazitises snails as well as humans. These Chaetogaster worms eat larvae (miracidia and cercariae) of trematodes and they are helping to snails in this way. The more Chaetogaster worms are on the snail, the the more intense trematode infection is.

I do not know how many trematodes were in snails or in the environment, but maybe lot of them.

Chaetogaster limnaei limnaei on Stagnicola sp.

Chaetogaster limnaei limnaei on Stagnicola spFrom time to time, I used to watch them and I was waiting for the time when they would multiply and when they will torture snail to death. It did not happen.

One day (do not know it exactly, probably few months later) I noticed that all worms disappeared. I did not know why they were gone.

Later I found the reason in the 1974 thesis. Chaetogaster limnaei limnaei is highly sensitive to temperatures above 24 °C. Such a temperature reduces or completely eliminates these worms. Therefore, If you transport worms from their natural environment to your tropical aquarium, there is no need to worry. If you have aquaria with aquarium heater, they are bound to be killed by high temperature. Worms are killed in summer heat as well.

All other photos show Chaetogaster limnaei limnaei on the same Lymnaea stagnalis specimen.

There does not seem to be anything strange from the general point of view. Nevertheless, there are still many worms on the snail’s body.

Lymnaea stagnalisChaetogaster limnaei limnei on Lymnaea stagnalisThey are in mantle cavity too.

Chaetogaster limnaei limnei on Lymnaea stagnalisDetail of one Chaetogaster limnaei limnaei on the left tentacle of Lymnaea stagnalis.

Chaetogaster limnaei limneiFew Chaetogaster limnaei limnaei on the left tentacle of Lymnaea stagnalis.

Chaetogaster limnaei limneiOne Chaetogaster limnaei limnaei.

Chaetogaster limnaei limneiReferences

Hopkins S. R., Wyderko J. A., Sheehy R. R., Belden L. K., Wojdak J. M. 2013: “Parasite predators exhibit a rapid numerical response to increased parasite abundance and reduce transmission to hosts“. Ecology and Evolution 2013; 3(13): 4427–4438.

Sankurathri C. S. 1974: “Effects of thermal effluent on the population dynamics of Physa gyrina Say (Mollusca: Gastropoda) and its helminth parasites at Wabamun Lake, Alberta“. Thesis, Department of Zoology, The University of Alberta, Edmonton, Alberta, 132 pp.


7 thoughts on “How to remove Chaetogaster limnaei limnaei

  1. I have such worms on a (probably) Radix auricularia snail I have collected from a lake on my recent trip to a friend of mine, around a week or two ago. A couple hours ago I have placed the snail in a small aquarium with a heater, set the temperature to around 28 degrees Celsius. The worms seem to be still hanging on, how long do you suppose will it take to weed them out ?

    P.S. I have left you a message on Facebook also, it should be available under the url, please reply in your spare time.


    • Hello, I think it will take a long time when Chaetogaster worms will die. I wrote ” few months later” on the blog. I am sorry, but I do not remember how many months it exactly was.

  2. Hello, I very much like your photos of the Chaetogaster. Do you own them and if so would you be happy for me to use them? I’m a PhD student and would like to include one in a poster. Many thanks!

    • Hello Alice! Thanks for your message. Yes, sure, use these my photos. The whole my blog is under the CC-BY-4.0 license. Credit me as author of the photo if you can. Thank you. Cheers,

      • Hi Michal, thank you! I used your “Few Chaetogaster limnaei limnaei on the left tentacle of Lymnaea stagnalis” photo and have credited you.

  3. Do you have more information on human infection? Do you believe a human could get infected through contaminated well water? I had the water tested and it came back positive for nematode. As did my stool sample but what I see under the magnification looks like chaetogaster. And they seem to link together. I would like to share some photos with you if you could email me. I would appreciate it.

    • Dear Sabrina,
      thank you for your comment. Chaetogaster does not infect humans and Chaetogaster does not belong to nematodes. So you are dealing with completely different animal. I would recommend for you to search for information on different websites, that focus on human infections related issues. Thank you. Good luck,

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