Wednesday, June 13, 2012

Yellow Slime Mold That Isn't

 Yellow Slime Mold has been showing up in the woodchips and dead logs at Springbrook lately.  If you see it shortly after it "erupts" it looks like a plate of macaroni and cheese. Really!

But it turns out that it is not a slime mold at all, or even in the fungi family.  Science has reclassified it as an Amoebozoa. Kind of like the very old scary movie "The Blob."  But this one is real, and it eats micro-organisms in dead plant material, helping with decomposition. 
Scientists have determined that what appears to be a "mold" like organism is actually thousands of protozoa like amoebas that behave very differently when they come together.  Under the surface they first form these filiment-like "gatherings" and within an hour or so they multiply and sort of bubble up to the surface, as you can see in the next picture.
 Within another hour this "blob" grows and becomes shiny and wet.  It may get big enough to cover a dinner plate, and 2 or 3 inches high on the top of the surface of the woodchips.
 It begins to fade after a few hours, and by morning it has lost its color, and is either some tan filiments, or a faded brown blob that must be dead amoebas, because it stays for days until washed away, as can be seen in the pictures below.
 I think this picture is remaining amoebas escaping back into the woodchips. 

Writing this blog gets me to double check my facts, and also learn new things.  For many years I have been telling folks about slime molds, thinking this was one. 

What is great about science is that it keeps checking on itself, and when a mistake is discovered, it corrects itself, and everyone moves on with the new knowledge.  Wouldn't it be great if that worked for other life issues as easily?
This Yellow Slime Mold that isn't is very interesting, and I hope some time to look at it under a microscope.  Maybe I can get some pictures and post them here.


  1. Very nice photos - thanks for posting!
    My high school students are doing research projects with Physarum polycephalum (slime mold). It is incredible the amount of research that has been going on in the past 15 years with this remarkable organism.

  2. Excellent photos and text on amoebozoa. I hope you dont mind but I have linked into my own blog to show against some I found the other day.