Saturday, November 2, 2013

Stemonitis

Just reached photos I made during the hike this August.
So, this post is, again, about me exploring North American flora/fauna.
That day I decided to use only 60mm macro objective and I think results are pretty interesting.

First fungus I found appears to be an easy one. I almost immediately found it in the book.


S.splendens / S.axifera / S.fusca
There are several species of Stemonitis which hard to tell apart without microscope (or DNA sequencing), in a books they mention only three. And to be more precise it is not a fungus, but slime mold. They grow on decaying trees (nothing new here) from May to October.
They are very abundant and grow everywhere (no surprise that I found it first).
Wiki says that this molds need only 20 hours to develop sporangia. So, it looks like if I would visited the spot by the end of the day the sporangia, at the bottom picture, should be already fully open.
These guys belong to a very distinctive group of organisms formally known as Myxomycota. And basically they are group of  amoeboid protozoa.   On a video below, at the beginning,  Stemonnitis shown in a plasmodium stage. It means that each of these small white spheres are single cells. They grow to these enormous sizes by acquiring all nutrition they can find. And at this stage only nuclei are dividing. Then each plasmodium produces a fruiting body.

For review: Keller, H. W. and K. L. Snell (2002). "Feeding activities of slugs on Myxomycetes and macrofungi." Mycologia 94(5): 757-760.
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