Freshwater Crustaceans found in Spring Water

Subject:  bug id
Geographic location of the bug:  Santa Cruz Mountains
Date: 08/08/2019
Time: 08:45 PM EDT
Your letter to the bugman:  Found these bugs in my spring water filter, and a few in my tank.  Any ideas?
How you want your letter signed:  lesley obermayer

Freshwater Crustacean

Dear Lesley,
We cannot provide you with a species identification, but this is some type of Freshwater Crustacean, probably an Amphipod or Isopod.  Most Amphipods are found in saltwater, but they can also be found in freshwater, including in caves.  According to BugGuide:  “A clear view of the antennae is needed to identify freshwater amphipods beyond order level.”  The only freshwater species pictured on the Natural History of Orange County is
Gammarus, and we would eliminate that as a possibility.  California Fish and Game has an online paper entitled Checklist of inland aquatic Isopoda (Crustacea: Malacostraca) of California, but there are no images.  BugGuide has an image of an Isopod in the family Asellidae and the genus Lirceolus that looks very similar to your individual, and we would attempt additional research by searching for members of the family Asellidae found in California.  The previously noted paper by California Fish and Game includes many family members, but again, there are no images.  This could be a rare endemic species, or it might be an exotic introduction.   Though we cannot provide you with anything more specific, we do feel confident that their presence will not adversely affect the quality of your spring water.

Freshwater Crustaceans
Dear Daniel,
Thank you so much. You appear to have identified our bugs.
Now we have to figure out how to eliminate them. Appreciate you taking the time and trouble to help us out.
Enjoy your days,
Lesley Obermayer
Freshwater Crustaceans

You are welcome.  You might want to check with your local natural history museum for a more definitive identification.

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