Smart Slime

June 7, 2022
A close up photo of chocolate tube slime molds
Photo by Kelly Volz
by Cassie Barnes, Digital Communications Specialist
Let's talk about slime molds, which are one of the weirdest and most astonishing lifeforms growing around our forests.
These here are called chocolate tube slime molds. Despite their name, they're not a mold or any kind of a fungus. These extraordinary little weirdos are actually single-celled amoeba-like organisms. The chocolate tube slime molds are a type of plasmodial slime mold that starts out as a single cell. But they find other slime mold cells and begin to join together to form one giant super cell that has several nuclei (where the DNA lives).
Think of it this way. You have a bunch of water balloons and inside each one floats a little ball (the cell nucleus). The balloon is the cell membrane. All of those water balloons merge together to make one giant balloon filled with water and each little floating ball from the smaller balloons. That, in a broad sense, is a slime mold.
These giant single cells then move around the forest to find food. They're usually found on rotting wood and forest litter, as their preferred food is the bacteria that breaks down these substances. While they move around, slime molds use chemical signals to communicate with each other.
When it comes time to reproduce, slime molds act similarly to fungus. They produce stalks and "fruiting bodies" (like in this photo) that send spores out in the environment. Those spores then turn into the cells, begin to look for food, and their life cycle begins again.
What is really amazing about slime molds is what scientists have discovered in the lab. When placed in a maze with a food source at the end, slime molds can navigate the maze. They also can be trained to expect a food reward at a certain place and time and will navigate to that place to get the food at the right time ... kind of like if your dog gets dinner every day at 5 pm, they let you know when it's 5 pm.
And they do all of this without a brain.
(To compare, I'm an actual human with a brain and I can't navigate my way out of a corn maze even if you promise me a funnel cake at the end. -- Cassie)