The Effect of Different Food Sources on Slime Mold Growth and Memory

Abstract

Physarum polycephalum is a species of slime mold that spends most of its life cycle as a plasmodium, a unicellular multinucleated amoeboid. This species of slime mold is well known for its spatial memory. Oats, quinoa, and barley have a lot of protein and nutrients; therefore, they were used to feed the slime mold. Other studies tested the memory or growth of slime mold. This experiment compared both slime mold growth and memory using oats, quinoa, and barley. It was hypothesized that barley would make the slime mold grow the quickest and largest due to its high protein concentration. Into 3 Petri dishes a culture of slime mold, and each food source was placed. The slime mold was then placed in a shoebox, with graph paper taped to the bottom, to make sure there was minimal lighting. After sections were cut out and placed into the remaining petri dishes with the same food sources it grew in and then placed into a Lego maze with the food sources to track the time of its memory. Barley and oats tied for overall growth after 48-hours, but barley-fed plasmodium grew much faster. It was hypothesized that the maze portion of the experiment, barley fed slime mold, would also complete the maze faster. The hypothesis was not supported. Oat grown slime mold completed the maze the fastest. The slime mold was placed into different mazes and allowed to grow for 48 hours. After 48 hours the hypothesis was concluded to be unsupported.

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