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Cytoplasm seeks efficient routes: slime mold


Physarum polycephalum / Stephanie Da.. / LicenseCC-by-nc-sa - Attribution Non-commercial Share Alike

Cytoplasm of slime molds creates efficient connective networks using adaptive foraging strategies.

The slime mold, Physarum polycephalum, is an extremely effective forager capable of creating extensive and highly efficient networks between food sources. This single-celled creature, classified as a protist, oozes its way across surfaces in search of bacteria, fungal spores, and other microbes to feed on. As it spreads and grows in search of food, it naturally organizes itself into a network of tube-like structures that quickly and efficiently connect its disparate food sources.

Physarum maximizes its ability to find food by ‘remembering’ and strengthening the portions of its cytoplasm that connect to active food sources. By rhythmically contracting and expanding its body, Physarum is able to move and grow its body in search of food. When it fails to find food or the food source dries up, Physarum retracts its cytoplasm, leaving behind a trail of slime--essentially marking which pathways are useful and which are dead-ends.

By trimming back connections and maintaining only active pathways, Physarum uses the least amount of resources and energy possible while still creating a resilient and fault-tolerant system. Links between food sources are made covering the shortest possible distances, but are connected in such a way that a disruption in one area does not impact the overall health or efficiency of the slime mold’s network.

Check out Physarum in action in this video.

This summary was contributed by Emily Hoehn.

"The body shape of the plasmodium resembles an intricate network of tubular components...During locomotion with a speed of 1 cm/h, the size and mesh of tubes evolve depending on the position within the organism. At the frontal part of the plasmodium, small components of the tube are very densely connected and some of the small tubes gradually become thick, while most of them disappear towards the rear." (Nakagaki 2001:767)
"After several hours, parts of the plasmodial body which extended into the dead ends of the maze retracted and moved to the food sources to wrap around the surfaces of the food source… From the viewpoint of solving a maze, the plasmodial tubes lie only in all possible routes which connect to the food sources, so that all solutions are indicated by the connecting tubes. Several hours later, the connecting tubes were cut off at one place and disconnected, except for the tube in the shortest connecting route." (Nakagaki 2001:767) 
"By lying only in the shortest route between two food sources, the plasmodium can deliver much of its own body to the food sources, so that the intake of the nutrient is more efficient. Moreover, since the tube is a channel of protoplasmic streaming, the shortest tube leads to efficient transport of protoplasm." (Nakagaki 2001:767)
About the inspiring organism
Med_6332392_364e15a963_b Physarum polycephalum
Physarum polycephalum Schwein., 1822

Learn more at
Some organism data provided by: Nomenclatural Database of Eumycetozoa (Myxomycota)
Organism/taxonomy data provided by:
Species 2000 & ITIS Catalogue of Life: 2008 Annual Checklist

Bioinspired products and application ideas

Application Ideas: Energy-efficient transportation and communication networks.

Industrial Sector(s) interested in this strategy: Transportation, Communication, Computer Science, Networks

Laboratory of Cellular Informatics
Toshiyuki Nakagaki
Research Institute for Electronic Science, Hokkaido University
Prof. Andy Adamatzky

Director of the Unconventional Computing Centre at University of the West of England Bristol
Tero A; Takagi S; Saigusa T; Ito K; Bebber DP; Fricker MD; Yumiki K; Kobayashi R; Nakagaki T. 2010. Rules for biologically inspired adaptive network design. Science. 327(5964): 439-442.
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Adamatzky A; Jones J. 2010. Road planning with slime mould: If Physarum built motorways it would route M6/M74 through Newcastle. International Journal of Bifurcation and Chao. 20(10): 3065–3084.
Learn More at Google Scholar Google Scholar  

Adamatzky A; Alonso-Sanz R. 2011. Rebuilding Iberian motorways with slime mould. Biosystems. 5(1): 89-100.
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about 1 year ago
is there any possibility that the slime - like animal scenting,urine and stools- contain information and built in time info to allow a previous rich source to recover and be re-used?
about 1 year ago
This strategy is very interested.
over 6 years ago
Here's an article, ScienceShot: Even Slime Molds Make Mistakes from Sept. 7, 2010: Just because an organism doesn’t have a brain doesn’t mean it can’t think. Researchers gave single-celled slime molds a “food test”: In the easy exam, the funguslike organisms had to decide between eating 2%, 6%, or 10% concentrations of oatmeal in inedible agar—a fairly clear distinction. In the hard exam, they had to choose between oatmeal concentrations of 6%, 8%, or 10%—a more subtle difference. Molds that chose faster were five times more likely to choose the worst possible option. But they didn’t always respond like humans do. When comfortable, the organisms made quick decisions if the choice was easy and took their time if it was hard. But when the team starved the molds or shined harsh light on them, they chose faster when the choice was hard and slower when it was easy. This counterintuitive behavior may be related to risk, the researchers will report online tomorrow in Proceedings of the Royal Society B. In the hard exam, the worst possible option (6%) wasn’t so bad, but in the easy exam, the worst option (2%) was dismal. So hungry molds had a lot to lose if they chose wrong.
over 7 years ago
Thanks to John Siddharth for contributing this strategy.
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