Slime mold networks

As I passed through a eucalyptus grove on campus, something brilliant yellow caught my eye. I bent closer. A gloopy, ruffled smear of yellow covered a curl of eucalyptus bark. Tendrils crept out from one end. A slime mold? I took a picture and uploaded it to iNaturalist when I got home.

iNaturalist is a website or app in which you can upload photographs of living things, tag their location, and add your guess of an identification. The site's artificial intelligence suggests possible species to help you with your identifications. Once you put up a picture, other people can confirm your i.d. or suggest an alternative. The site suggested dog vomit slime mold-- Fuligo septica-- for my picture. I don't know much about slime molds but that sounded like a good description of what I'd seen!

The next day, Sarah Lloyd, a slime mold expert from Tasmania, Australia had left a comment on my post: "It's the plasmodial stage of a slime mould that's still transforming. Can you return and get a photo of mature fruiting bodies?I don't think it's Fuligo. It's more likely to be Leocarpus fragilis; the substrate looks right and the species seems to be extremely common at the moment in California." I went back to the same spot two days later, and there was nothing yellow to be seen. I started poking around, and found tiny brick-red bulbs coating the eucalyptus bark on the ground.

It was indeed Leocarpus fragilis! This slime mold, like others in its class, spends much of its life as a tiny single-celled organism. But after rain, it is able to find much more of the bacteria and fungi it eats, and the cell begins to expand dramatically. That blob of yellow slime I saw was one single enormous cell! The cell send out thin tendrils searching for nutrients. A slime mold in this phase grows into a web or network, passing nutrients through its pathways, growing thicker where conditions are good. Researchers have found that slime molds can solve mazes and generate efficient solutions to problems of how to connect a set of dispersed resources. Slime mold networks can take a range of forms.

Eventually, the slime mold transforms again, forming fruiting bodies where spores grow. These spores are eventually dispersed and start the life cycle anew as individual slime molds.

There's an interesting parallel I think, between the lives of slime molds and our new human way of living with the internet. Slime molds build networks and webs, finding and passing nutrients. We form virtual networks and webs, finding and passing knowledge, lies, jokes, art, crap, and memes. This web connected my photo of a yellow smear to a naturalist in Australia who knew what it was, and sent me back to see a miraculous transformation.

iNaturalist

Sara Lloyd's website

Article about Sara Lloyd from iNaturalist NEW!

Intro to slime molds from the University of California Museum of Paleontology at Berkeley

Slime mold intelligence from Nature