The Amateur Mycologist #35 - Likely Licea variabilis Slimemold Grown In Moist Chamber - Morphological Transformation Caught On Time Lapse - In Depth Analysis
These strange fellas appeared overnight.
I was scanning this particular piece of wood quite frequently under the dissecting microscope. As a result, I was checking it every day in effect, toying around with different angles and lighting.
So, imagine my surprise when, over the course of a single night, I woke up and found these shiny, jelly masses adhering all over my little piece of bark. I thought I had finally hit the slime mold jackpot! This looked like it could possibly be a plasmodium... a bit large and robust and sudden to be sure, but, why not?!
So, I decided to hedge my bets and try to take a time lapse. Maybe, just maybe, I would capture something awesome
"Taking a time lapse" turned out to be less than straightforward.
On the one hand, the AMscope software makes taking a time lapse video about as easy as possible. In this case I set the program to take 1 picture every minute for 8 hours. I ended up needing to turn it off in the middle of the night, about 5 hours in, because the light was keeping me and my wife awake. This is all happening in my tiny bedroom laboratory after all.
Unfortunately, time lapse photographing a slime mold, or even a growing fungus, is more complicated than simply setting up the camera and leaving it. These organisms can be extremely sensitive to both light and moisture content. At the same time, my camera requires a certain amount of light, even at the highest exposure, in order to capture anything.
So, I spent an hour working out a perfect balance. First, I knew I could not remove the cover of the petri dish. To do so overnight would dry the entire ecosystem out, probably fatally. However, second, I found that if I left the dish cap on and allowed for direct LED illumination, even at low levels, it caused a slight increase in temperature, which in turn caused a TON of condensation.
I needed to get as little light as possible on the specimen while maintaining the ability to visualize what was happening. Above you can see my extremely make shift approach. The petri dish is ensconced in towels to help maintain an even temperature, as my bedroom can get drafty at night. Meanwhile, the light is turned down to its lowest setting, and I've inserted small slivers of white paper to help reduce the direct light even further.
The results of my efforts are below. The video encompasses about 4 to 5 hours at 24 frames per second. You will see that my light/heat tricks worked, as the condensation slowly recedes as the video progresses. You will also see that, although it is not plasmodial movement, I do in fact capture something pretty strange.
Keep your eye on the fruiting bodies at the bottom of the video.
What? FUNGAL BLOB is evolving!
That is not a trick of lighting - the lighting stayed even all night long - the fruiting bodies matured overnight!
How crazy is that?! Overnight, the strange organisms, which had only appeared less than 24hours earlier, morphed super quickly into a totally different look. The almost clear fruiting body structures became completely opaque, and differentiated between a thin outer skin and a brown, fig newton colored and textured spore mass.
Moreover, the transformation happened uniformly across all of the fruiting bodies on the piece of bark. There were about 8 of them altogether, with the larger, measurable by calipers, coming out at 1.9mm at its widest. Each cap was fairly well dispersed across the bark, and yet all of the caps appeared and matured at nearly identical rates.
Finally, and this is the really crazy thing, the bulk of the change occurred within about a single hour. It's almost like a chemical reaction - it took a little while to get started, but once it got rolling, the transformation was quick and inexorable.
I needed to get an interior sample to examine under the compound microscope - so I thought it would be helpful and interesting to capture some footage of that process. You can see the Fig Newton like color and texture of the spore mass. I'll make a reverse .gif of this as well, cause I think that would be oddly satisfying.
Once the sample was taken, I placed it under the compound scope.
These spores looked vaguely circular, but with ill defined edges.
These are from a sample I took the morning after the time lapse. I waited a couple of more days and then returned to take a new sample, thinking that something might have changed. It did.
These are the beautiful, round spores taken from a different cap of the same species several days after the transformation.
You can see that the spores are now very clearly defined in their shape and color. It's hard to say without the 100x immersion oil lens, but based on the well defined outer edge of each spore, I would guess that these spores have a fairly thick skin or "Perispore."
I took measurements of a few and they ranged within roughly 12-13ish microns in diameter.
As always recently, we are left with the burning question - what are we looking at exactly?
I now believe that this is Licea variabilis - a myxomycete!
However, getting there was a process.
If you take a look at the sources for this post, you'll see that there are a bunch. I run these tiny finds through all of the guides I own, then through all the internet resources I know about, and in this case even through google scholar looking for more comprehensive and obscure keys and scientific papers.
Here, there were several species/genuses that I encountered that seemed plausible at first, but didn't work. The Exidia genus contains some species that look like an OK match on the surface. Take Exidia glandulosa to the left. However, the species, and most of the species in Exidia I could find had very specific, sausage shaped spores, unlike the very round ones present here.
The Daldinia genus also came to mind. However the species I could find all seemed to grow on a totally different scale, in the 1+ cm range, than the species I found here. Now I've heard that moist chamber grown specimens don't always grow to their normal ranges, but this would be a stretch. Plus Daldinia concentrica, to the right, is a Ascomycete. The spores shoot out through the surface of the fruiting body, and they are a different shape overall.
The specimen we have here doesn't appear to be an Ascomycete. I've returned to look at the fruiting bodies several times in the last week or so since they matured and they don't seem to have expelled any spores like an Ascomycete would. Plus, the roundness of the spores seems to militate against the idea that they would be shot out of asci, a structure which I did not see under the compound scope.
The organisms I'm looking at here seem closer to the final product of Lycogala epidendrum, or one of the fungal puff balls. I will keep watching them to see if/how they actually disperse their spores. So far, given the ease with which I damaged them, I think it might be by means of physical agitation. However it could be that they form a dispersal hole in coming days. To be clear, these are NOT L.epidendrum. The spores are too large and the fruiting bodies are morphologically quite different.
Another option up for grabs was a Hypoxylon species. I only considered the genus after finding one in Baroni's field guide. He covers one species, H.fragiforme. However the spores are ellipsoid and the surface of the fruiting body is textured differently.
Eventually I Discover Life and slimemold.uark.edu, both very comprehensive online resources for Myxomycete species.
After going through a number of illustrations on slimemold.uark.edu, I began to see similarities in the Licea genus. So I went through all of the illustrations in that genus and eventually came to one for L.variabilis, cited to below. It looked perfect! A round spore with a sessile aethalium that shared the basic morphological traits I was seeing.
I looked up the species on Discover Life, also cited below, and found that it largely fit the bill in other ways. The spore size averaged between 12-13 microns, and the bodies began, according to the website, were "tan colored" when young. To be fair, mine were straight up whitish transluscent, but they did go through a brief tan phase in the time lapse.
The thing that made me doubt this being a slime mold in the first place was the failure to see any kind of plasmodium in the lead up to the sporangia appearing. However, that seems to be supported by the abstract of a resaearch article I can't reach because it's behind a paywall, indicating that L.variabilis does not produce a protoplasmodium.
Given all this, I feel fairly certain that this is a Licea species, and similarly confident that it is, in fact, L.variabilis or a variant thereof.
Photos And Videos Are My Own Except:
By This image was created by user Dan Molter (shroomydan) at Mushroom Observer, a source for mycological images. You can contact this user here. [CC BY-SA 3.0 (https://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons
Microscopic photos were taken using an AmScope SM-4TZ-144A dissecting microscope and an AMScope M150B entry level microscope. The camera lens is also AMScope, MU300.
The bulk of the information in this case was derived from a multi-part posting of these photos and the circumstances of their being taken on several forums involving the study of Fungi and Slime Molds. The information was shared on The Slime Mold Collective, The NYMS Facebook page, and the subreddits /r/mycology and /r/slimemolds. Users from the slime mold collective and reddit both expressed doubt that this was a slime mold and was in fact a fungal mold.
Efforts were made to identify the species using the following books:
1 Myxomycetes A Hand Book of Slime Molds By Steven L Stephenson and Henry Stempen
2The Audubon Society Field Guide To North American Mushrooms by Gary Lincoff, p.382, Exidia glandulosa.
3Mushrooms Demystified By David Arora
4Mushrooms of the Northeastern United States and Eastern Canada by Timothy J Baroni, p.563, Hypoxylon fragiforme