Mushrooms are the favorite food of slime molds

 Today, I'll show you how much slime molds love the mushroom by a little experiment. As you know, slime molds are not a fungus or a plant. In their slimy stage, they usually creep through the forest growing in size and digesting food, probably mushrooms.

I happened to find a yellow slime mold living on a dead branch lying near my house about 2 years ago. Since then, I have been taking care of it on a agar plate feeding them with oat granules (for oatmeal) and transplanted it every 5 or 6 days. 

I classified it as Physarum rigidum by the color and shape of its fruitbodies. This slime mold much favors raw mushrooms sold in a grocery store rather than dry oat granules. 

Let's get down to the main topic. I put a mushroom covered fully with this slime mold on a agar plate and also placed an intact mushroom next to it. (at AM 9:36, May 1st)　This mushroom is 'buna shimeji' and  its scientific name is Hypsizygus marmoreus.

After approximately 5 hours, I noticed slight changes in the slime mold on the mushroom. This may be a sign that something is going to happen.

After approximately 11 hours, the slime mold started spreading at last.

After approximately 15 hours, the slime mold extended widely and covered the adjacent mushroom. 

After approximately 20 hours,  the slime mold seems to be absorbed in feeding a new mushroom and maybe stop moving further for a while. 

In my experience, mushrooms seem to be the best food for this slime mold. But the problem is that saprophytic bacteria are actively growing and will form translucent colonies around the mushroom. These bacterial colonies could hinder the growth of slime molds.

↓　Since bacterial colonies surround the mushroom, slime molds are kept away from the mushroom. In this case, this mushroom is 'Shiitake' and  its scientific name is Lentinula edodes.

Therefore, I usualy feed oat granules to the slime mold, although the slime mold can't grow vigorously compared with raw mushrooms.　Oat granules are low-priced and can keep for a long time.