Great Lakes Worm Watch

Research Methods

Preserving earthworms

So, once you have earthworms, what do you do with them? If you are documenting an earthworm occurrence or want to save your specimens for identification later, then you need to preserve them.

  1. Kill the earthworms in alcohol
  2. (isopropyl – rubbing alcohol works great)

    1. Get as much dirt off the earthworms as possible
    2. Put the earthworms in the alcohol one at a time (rather than a whole handful all at once) so they don’t get tangled up into a big mess of earthworms. After a few seconds, the earthworm will become anesthetized and relax into a mostly extended position.
    3. Place the anesthetized earthworms into a vial. You can keep the earthworms in alcohol for up to 24 hours (keeping them cool and out of direct sunlight). But don’t wait to long, after a day or so in alcohol they start to get mushy.

    Within 24 hours you need to:

  3. Put the earthworms in Formalin
    1. Place the earthworms in a leak proof vial and cover them in Formalin which is a cellular fixative that will prepare the specimens for long-term storage.
    2. Once the earthworms have been in formalin for at least 24 hours, they can be placed back into alcohol (70-100% isopropyl, NOT ethyl which bleachs any pigmentation) for long-term storage. This allows you to re-use the formalin over and over again.

    CAUTION: Formalin is a dangerous chemical and safety precautions must be taken. It should be used only in a well ventilated area. It should not be breathed, swallowed or come in contact with bare skin or eyes. If external contact does occur wash the area with large amounts of water. If ingested contact a poison control center immediately. Formalin has been shown to cause cancer in laboratory animals.

If you do not have access to specimen vials and formalin, we can provide them. Contact us greatlakeswormwatch@gmail.com

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