Field of Science

The Blob - It lives!

Just as the Phactor was getting old enough to go to movies, scifi was all the rage, but the special effects back then were pretty cheesy, so you never got too scared. In 1958 The Blob featured a space alien (back when being alien always meant from outer space, not just somebody from next door) that consumed all life forms. Wow, what a concept! Oh, and who starred in that movie even though he wasn't really cool yet? So imagine what a thrill it was to find out that the blob really exists in the "body" of a plasmodial slime mold, a multinucleate sac of flowing cytoplasm that consumes all life forms it can engulf. See how similar they look? Plasmodial slime molds are the T. rex of the unicellular world, the most fearsome predator on the cellular world. The cytoplasm within the plasmodium flows back and forth in channels formed by stiffer cytoplasm (actins and actin binding proteins), and like waves coming ever higher on the beach with the incoming tide, the plasmodium surges in one direction or another allowing the beast to "crawl" in a amoeboid fashion. The biggest (This one is only about 20 cm across.) and most impressive makes its appearance just about this time of year because people have been spreading bark mulch around garden beds, and all those bacteria and fungal spores are just so tasty, waiting there to be engulfed by a blob of cytoplasm in the form of Fuligo septica, often affectionately called "dog vomit". Often the plasmodium is bright yellow when they appear, but exposure to light stimulates spore formaton resulting in a change in pigmentation and the plasmodium will darken to a brownish mass of spores.


Anonymous said...

Some big ones here in the woods as there's been quite a few heavy thunderstorms, with wet, hot conditions and plenty of dead leaves and earthy-mass to overgrow.
We didn't, on our dog walks, know what it was, but now we do, thanks to you! And we can't blame our dogs for being sick, either... ha ha...
Thanks for your time and enjoyable science.
Dennis Hermanson
Hillsborough, NC USA

The Phytophactor said...

TPP aims to please and amuse.