Field of Science

Reticulose amoeba: cells can be fine nets too

Again, the protist kingdom is a special paradise for a cell biologist: as soon as one steps outside the plant and animal kingdoms (and yeast), diversity of cellular forms and structures explodes beyond reason. Cells can also take the shape of a fine net with no obvious cell body proper:

Cover slip floated ~ 1wk on marine sample from intertidal silt at Stanley Park. (40x obj, DIC and phase, resp.)
EDIT: Confirmed Filoreta.

Almost overlooked it thinking it was just slide gunk. Amoebae suffer all too often from that fate – apparently Parvamoeba, one of the most common and ubiquitous amoebae, was only described in the early 90's (Rogerson 1993 EJP) because it was tiny and no one noticed.

Could be something like Filoreta sp. (Rhizarian), but something feels off about it. Filoreta doesn't seem to stretch cytoplasm between filopodia like this specimen does. Maybe it's more like the amoebozoan Corallomyxa and Stereomyxa, or stramenopile Leukarachnion. Then again, amoebae are notoriously dynamic in their morphology. Something that's a far bigger issue in the microbial world is the necessity of getting a sense of the morphotype range of a species; one specimen doesn't quite cut it as it does for animal taxonomy.

In fact, perhaps instead of the ridiculious (for us) ICZN and ICBN requirements for submission of material for curation (many species neither like being cultured nor preserve all that well on a slide), for microbial species there should be a requirement for additional images of different specimens, if possible, to try to capture some of the morphological range. But then again, I'm not a taxonomist, so what do I know.

Right, midterm... (hey, at least I procrastinate productively!)


  1. This looks amazing!
    If you happen to stumble upon some plastids in the cell bodies it could also be something along this line ( they've never been found that far north.

    Great pix by the way :o)

  2. Chlorarachniophytes are indeed awesome, but I'm afraid I won't get to see any wild ones unless someone buys me a vacation in the tropics... ;-)

    Kinda wish Filoreta branched basally to Chlorarachniophytes, could make for fun storytelling. But alas, they don't. I don't remember if Filoreta has any flagellates or cysts... but the fusing filose amoeba colonies seem to be common around that part of the tree.

    I'll blog about Chlorarachniophytes eventually. So many weird things about them, possibly partly because their plastids have attracted enough attention for those oddities to be found.


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