Slime Mold: Moving and Problem Solving

Fuligo septica, Gelbe Lohblüte, Hexenbutter

In a twist of nature, the slime mold, scientifically referred to as Physarum polycephalum, defies expectations by showcasing a level of intelligence and problem-solving prowess that belies its lack of a conventional brain or neurons. Within the diverse tapestry of fungal species, each with its own distinct attributes, this particular organism emerges as an exceptional outlier. Slime molds, to employ a modest description, stand as riveting entities that never fail to capture the imagination.

Key Takeaways: Slime Mold


  • Slime molds are a group of diverse and intriguing organisms that share characteristics with both fungi and protists. They are not plants, animals, or fungi.
  • The slime mold’s life journey encompasses two pivotal phases: an expansive plasmodial stage where a vast, single-celled, multinucleated entity emerges, and a subsequent reproductive phase birthing spores into existence.
  • Dwelling in diverse habitats such as woodlands, decaying organic matter, and damp recesses, slime molds emerge as either glistening patches or intricate, labyrinthine structures.
  • With a diet composed of bacteria, fungi, and other microscopic life forms, slime molds employ a strategy of engulfing their nourishment. These adept decomposers play an essential role in the intricate dance of decomposition and nutrient recycling.
  • Devoid of muscular tissues or a nervous system, slime molds bewilder with their dynamic behaviors. These organisms manage to move and maneuver, responding astutely to environmental cues, often forming elaborate and captivating patterns.
  • One particularly studied member of this group is the Physarum polycephalum, dubbed the “many-headed slime.” It has become a model for mimicking network structures and tackling intricate challenges, exemplifying the intricate tapestry woven by these enigmatic life forms.

Characteristics of the Slime Mold

Elaeomyxa Cerifera
Elaeomyxa Cerifera. Image: Sarah Lloyd.

The previously mentioned slime mold, scientifically recognized as Elaeomyxa cerifera, typically presents itself in scattered or diminutive clusters. As it progresses into the phase of sporocarp formation, wherein spores are disseminated, a remarkable spectacle unfolds. The organism undergoes a division, birthing glittering clusters of luminous spores that resemble miniature orbs of radiance. Consequently, the slime mold becomes adorned in a resplendent array of hues spanning the spectrum from regal purples and verdant greens to tranquil blues. Yet, this awe-inspiring facet of the slime mold’s existence often eludes the gaze of many, evading their observation throughout their lifetimes. For those yearning to witness this mesmerizing phenomenon, Tasmania emerges as a promising locale, offering the highest likelihood of encountering this dazzling spectacle when equipped with the appropriate tools.

However, let us now pivot our focus to the captivating entity that is Physarum polycephalum. A single-celled, yellow-hued slime mold, P. polycephalum, unfurls as an exemplar of remarkable morphological adaptability. Its appearance is exquisitely responsive to its environment and mode of growth. Within a sylvan realm, it metamorphoses into expansive, ochre-colored masses. Nestled beneath a leaf’s embrace, it takes on the semblance of fluid mustard. In the controlled confines of a laboratory, bestowed upon a petri dish, P. polycephalum unfolds in a contrasting guise. It coats the agar plate in a diaphanous layer, reminiscent of the sprawling arms of coral. What astounds is the symmetrical beauty of its branching pattern, which astonishingly mirrors the same intricate logic that governs phenomena such as lightning’s latticework, meandering river deltas, intricate neural networks, and the intricate pathways of blood vessels.

Slime Mold is Actually Not Fungal

In a twist of biological classification, the slime mold, contrary to common belief, does not truly belong to the fungal kingdom. Instead, it more closely resembles the classification of a single-celled amoeba and is known by the name “slime mold.” Its profile has been known since ancient times, with Aristotle documenting its characteristics over three millennia ago. However, its surge in scientific prominence only manifested itself in the 1940s. These peculiar entities flourish under the cool, damp, and dim conditions that characterize forest floors. Within this habitat, they find sustenance by consuming bacteria, protozoa, fungal spores, and various forms of decaying organic matter.

Upon their initial emergence, sporophores unveil a pristine white hue, often cloaked in a yellow waxy layer that might occasionally assume a pinkish tint. As these slime molds progress through their life cycle, the white outer layer undergoes a transformation, darkening in tone, while the persistent yellow layer retains its vibrant identity.

In the zenith of their maturation, fully developed slime molds exhibit an astonishing metamorphosis of their peridium, the external surface of the sporocarp. This outer layer becomes delicate, translucent, and takes on an iridescent quality. As the sporocarp commences its gradual rupture, it assumes the semblance of a delicately cupped leaf, with a vibrant array of spores emerging to decorate this tableau.

What Are the Types of Slime Molds?


Within the realm of slime molds, a taxonomy unfolds, culminating in two distinct categories: cellular slime molds, scientifically termed dictyostelids, and plasmodial slime molds, recognized as myxomycetes. These classifications serve as gateways into the intricate lives of these enigmatic organisms, revealing their diverse modes of existence.

Cellular Slime Molds (Dictyostelids)

Dictyostelids inhabit a realm of singular individuality until conditions align to orchestrate a remarkable transformation. Each cellular slime mold stands as a solitary entity, a single cell navigating its microcosmic world. Yet, when the environment issues a clarion call, dictyostelids respond with an astonishing display of collective behavior. The solitary cells convene, uniting their microscopic might into a communal endeavor. The result is a multicellular aggregate, a tapestry of individuality that coalesces to form a complex structure. This alliance, aptly referred to as a “slug,” navigates its surroundings, serving as a testament to the power of unity in the face of adversity.

Plasmodial Slime Molds (Myxomycetes)

Contrasting the narrative of dictyostelids, plasmodial slime molds unveil an alternative strategy for survival and expansion. These organisms embark on a different path, forsaking the solitary existence of individual cells. Instead, they transition into a mesmerizing phase of collective existence. The culmination of this transformation is the emergence of a plasmodium, a multinucleate mass that transcends the boundaries of a single cell. This plasmodium extends its protoplasmic tendrils, weaving through its environment like a living tapestry. A testament to both adaptability and ingenuity, the plasmodial phase enables these slime molds to navigate challenges and thrive amidst diverse conditions.

In the intricate dance of life, cellular and plasmodial slime molds embody distinct strategies, each a marvel of adaptation and survival. Their diversity serves as a window into the world of microorganisms, showcasing the remarkable ways in which life navigates the complexities of existence.

Slime Mold Can Move

Fuligo septica is a species of slime mold, and a member of the class Myxomycetes.
Fuligo septica is a species of slime mold, and a member of the class Myxomycetes. Image: Wikimedia.

The label “slime mold” may give a misleading impression. These organisms possess the remarkable ability to self-propel and even consume other single-celled entities. Astonishingly, these feats are accomplished without the presence of a traditional brain, rendering them more adept than humans in specific facets of their existence.

In the visual representation provided, a vivid tableau unfolds: a slime mold thrives upon the decaying trunk of a tree. Its vibrant yellow hue serves as a beacon, drawing attention to its intricate network of vein-like extensions, which act as pathways leading towards sources of sustenance. Interestingly, the collective entity you’re observing is not an individual organism but rather a conglomerate composed of thousands of individual slime molds.

However, it’s important to underscore that while the term “slime mold” is utilized, these organisms are far from typical molds. Their nature is more akin to that of amoebas, which are structured from microscopic, single-celled sacs that orchestrate movement through shape-shifting mechanisms. This intricately orchestrated choreography grants them an exceptional degree of mobility and autonomy.

Slime Molds Merge to Form One Body

Slime molds have a fascinating capacity to exist individually as single-celled entities. However, when two or more of these solitary organisms converge, an intriguing transformation takes place. Their distinct cell membranes dissolve, leading the cells to coalesce beneath a unified membrane. This remarkable phenomenon permits two separate slime molds, each harboring its own unique genetic identity, to harmoniously inhabit the same corporeal entity. Remarkably, there is no inherent constraint on the number of individual organisms that can participate in this collective endeavor, christened a “plasmodium.” Within this communal framework, every member contributes toward the collective good.

Upon introduction to a novel environment, slime molds embark on a remarkable journey. They extend in all directions, embracing a fractal pattern as they traverse the terrain. This expansion is predicated on the meticulous evaluation of the substrate’s arrangement. When encountering beneficial conditions, such as the presence of nourishment, slime molds chart a path toward them. Conversely, aversion to unfavorable circumstances, exemplified by sunlight, triggers a retraction.

His favorite foods are three to two proteins and three to one carbohydrates. In this sense, he also eats healthy.

These organisms exhibit a discerning ability to assess and select their responses to various situations. Rather than merely accepting their circumstances, slime molds exercise nuanced judgment, opting for conditions that best suit their survival. This seemingly straightforward decision-making process belies its complexity. These advanced capabilities enable slime molds to adeptly tackle impressively intricate challenges, transcending the boundaries of simplicity to conquer complex problems with remarkable efficacy.

Problem Solving Skills of the Slime Mold

Slime mold form a map of the Tokyo-area railway system.

Placing a handful of oats, the favored sustenance of slime mold, onto a map triggers an astonishing display of problem-solving ingenuity. The slime mold’s objective is clear: to establish the shortest viable connections between these delectable morsels. Even more intriguingly, when obstructions like salt, which repels slime mold, are introduced, these organisms embark on a quest to circumvent these hindrances through creative pathways. Such adaptive behavior is a testament to their remarkable cognitive abilities.

Researchers have uncovered a jaw-dropping revelation: when oats are strategically positioned at points that mirror a city’s bustling locales on a map, slime mold mirrors the city’s intricate rail system. This uncanny capacity was showcased when slime mold masterfully recreated the Tokyo subway map, a task that typically consumes years of human engineering efforts. The remarkable twist? Slime mold accomplished this feat within a matter of hours.

However, their cognitive prowess extends beyond urban planning. Confronted with mazes, slime molds deftly chart the optimal route to the exit and encode this information within their cellular memory. Astonishingly, individuals who successfully navigate the maze proceed to teach their fellow slime molds the most efficient pathway. The collaborative acquisition of knowledge ensures that a second slime mold completes the maze with even greater speed.

Further revelations point toward the slime mold’s innate sense of time. Exhibiting an aversion to cold and arid conditions, slime molds subjected to daily wind exposure gradually diminish in size. Remarkably, even when the winds cease, the slime mold doesn’t hasten to revert to its original state. Instead, it orchestrates its growth, slowing down and modulating its development in anticipation of a potential wind resurgence. This testifies to the organism’s ability to adapt and learn even without the conventional structures of a brain or nerves.

The mechanisms underlying these extraordinary feats remain a realm of ongoing exploration and inquiry. With a history spanning approximately 600 million to a billion years on Earth, far eclipsing the tenure of Homo sapiens by about 200,000 years, slime mold possesses a form of intelligence that is truly astonishing and deserving of profound admiration.

Slime Mold at a Glance


What are the types of slime molds?

Slime molds are categorized into two main types: cellular slime molds (dictyostelids) and plasmodial slime molds (myxomycetes). Cellular slime molds exist as single cells until they aggregate under certain conditions, while plasmodial slime molds form a multinucleate mass known as plasmodium.

How does a slime mold move?

Slime molds move using a unique mechanism. They can flow and change shape by extending portions of their cell membranes, allowing them to move towards sources of food, typically bacteria and other microorganisms.

What is the plasmodium of a slime mold?

The plasmodium represents a substantial, multinucleate cytoplasmic mass that materializes during the vegetative phase of plasmodial slime molds. This dynamic entity exhibits mobility as it envelops nourishing particles, and given specific environmental cues, it possesses the capability to undergo differentiation, culminating in the development of reproductive formations.

How does sporulation occur in slime molds?

Sporulation stands as the intricate mechanism through which slime molds generate spores to facilitate reproduction. Plasmodial slime molds take shape by crafting fruiting bodies, which subsequently discharge spores, whereas cellular slime molds congregate to construct a multicellular framework responsible for spore production.

Can slime molds solve complex problems?

Slime molds, specifically the species Physarum polycephalum, showcase an astonishing capacity to unravel intricate dilemmas, closely resembling certain cognitive processes employed by humans when addressing problems. They exhibit prowess in discovering efficient routes within mazes, and remarkably, they engage in the optimization of transportation networks.

What is Physarum polycephalum?

The species Physarum polycephalum belongs to the plasmodial slime mold category and is renowned for its remarkable aptitude in maze-solving as well as its distinctive behavioral patterns. Researchers have extensively examined this organism due to its potential applications in biological modeling and its capacity to tackle optimization problems.

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