Testate Amoebae

Click on the images to view movies of these testate amoebae
A live testate (shelled) amoeba, Hyalosphenia papilio with flagellate associates/endosymbionts inside the test moving around fast. We don’t yet know what type of flagellate this is, and have never before seen live amoebae with flagellates inside… The flagellates appear to be trapped (or happily) inside the test. All amoeba with associated flagellates in tests were found in one sample from Acadia National Park in August 2012.
Here is another Hyalosphenia papilio this one is actively moving with a psuedopod extended outside of the test. Two flagellates are visible inside the test.
Two ‘morphospecies’ of Hyaposphenia – H. elegans and H. papilio – can be genetically identical. Here, H. elegans (smaller amoeba) and H. papilio (larger amoeba) appear to be having sex. We hypothesize that these morphospecies are actually examples of sexual dimorphism.
More evidence of sex between H. elegan and H. papilio.
This is a Nebela sp. with many flagellates inside the test. Aperture (opening) again appears to be blocked.
A Nebela tincta with amoebae pushed up against aperture appears to be blocking exit. Numerous flagellates inside.
Hyalosphenia papilio with visible pseudopods. One flagellate is visible inside.
Nebela collaris with multiple flagellates inside test.
Nebela tincta with two flagellates.
Nebella sp. dividing – visible cytoplasm streaming from mother to daughter cell.