Mutualism | Definition | Types | Facts | Example

In this article, we are going to define mutualism. You undoubtedly already know that mutualism is a symbiotic relationship in which both organisms derive benefits. This sort of arrangement presents many diverse creatures, so let us look at this topic in detail.

Definition: What is Mutualism?

Mutualism is simply described as a partnership in which both species benefit from one another. This link can exist either inside a species or between two species. Symbionts are species that share this relationship.

All living organisms, including humans, animals, birds, plants, and other microbes such as bacteria, viruses, and fungi, have a mutual interaction. Mutualism is a symbiotic relationship.

Mutualism is a sort of partnership in which both the host and the symbiont benefit and no one is hurt. This partnership could last a long time or be short-lived. The name “mutualist” refers to the little partner, while “host” refers to the other participants in the Mutualism.

Ants, for example, live and feed on acacia tree nectar. The mutualists are ants, and the hosts are acacia plants.

The ants have a home and food in the acacia tree. Because they have hollow enormous thorns that serve as ant houses and yellow swellings on the leaves that serve as ant food. Ants, on the other hand, serve as a guard, destroying insects and defending the tree from grazing animals.

Types of Mutualism

There are five types of Mutualism.

1. Obligate Mutualism

The relationship between two species in which both are entirely reliant on each other is known as obligatory mutualism. The best examples of obligate mutualism are most symbiotic and some non-symbiotic symbioses.

For instance, consider the Yucca plant and the moth.

The yucca plant thrives in the southwestern United States’ dry and arid climate. The pollination mechanism of the yucca flower is dependent on the moth. By laying its eggs on the blossom and feeding the larvae with the seeds, the moth benefits as well.

2. Facultative Mutualism

The partners in facultative mutualism can coexist without relying on each other. They, on the other hand, create a diffuse interaction with a diverse range of species.

Honeybees with plants, for example. Honey bees visit a variety of plant types in search of nectar, and these plants will be visited by a variety of insect pollinators for pollination.

3. Trophic Mutualism

The partners in trophic mutualism are specialized in complementary ways of obtaining energy and nutrients from one other.

Take, for example, cows and bacteria. The cellulose of the plant is indigestible to cows. The bacteria found in cow rumens aid in the digestion of plant cellulose. Bacteria, on the other hand, receive food and a warm environment, both of which are necessary for their growth and development.

4. Defensive Mutualism

In defensive mutualism, one partner receives food and shelter in exchange for defending the other against herbivores, predators, and parasites.

For example The aphids and the ants. Honeydew is produced by the aphids and delivered to the ants’ nests at night to protect them from predators and accompany them. The following morning, these aphids are brought back to the plant. In exchange, ants benefit from the aphid’s eggs, which they assemble and store in their nest chambers to withstand the chilly winter months.

5. Dispersive Mutualism

In dispersive mutualism, one partner receives nourishment in exchange for assisting flowers with pollen transmission.

Honeybees with plants, for example. Honey bees fly from one bloom to the next in quest of nectar, which is needed to make honey; in exchange, plants gain from pollination, as the honey bee spreads pollen from one plant to the next.

Facts About Symbiotic Relationships

When two species interact in a way that benefits one or both of them, this is known as a symbiotic connection. Symbiotic connections are classified as facultative or obligatory by biologists. The organisms in facultative partnerships can exist without each other. If one or both creatures in an obligatory relationship were to be separated, one or both would die.


When both lifeforms in a partnership benefit, this is known as mutualism. Humans, for example, provide food and shelter for dogs, while dogs provide companionship and protection. Because people and dogs may live without each other, this is a facultative relationship. Mycorrhizae, which means “fungus-root,” is a type of mutualism found in around 80% of plants. A fungus in the soil called mycorrhizae uses threads called hyphae to attach itself to a plant’s roots. The hyphae transport necessary nutrients to the plant, while the plant feeds carbohydrates to the fungal. Plants in low-nutrient areas benefit from this because it allows them to acquire important minerals like phosphorus. Because fungi do not create their own food, it is beneficial to them.


When one organism benefits while another, or host, is not hurt or aided in any manner, this is known as commensalism. Small jellyfish relatives are known as hydroids, for example, move to their feeding areas by sharing snail shells with hermit crabs. Because hydroids and crabs eat different diets, the crabs are unaffected. Inquilinism is a type of commensalism in which one organism uses the habitat or species of another without affecting the host species. Some mosquitoes, for example, protect themselves by spawning and dwelling in the fluid inside pitcher plants.


When one organism profits while the host suffers, this is known as parasitism. Parasites, unlike predators, do not kill their hosts. Parasites, on the other hand, obtain food or shelter from their hosts throughout time. When parasites are left untreated for an extended period of time, they can cause sickness and even death. Parasites include a vast range of worms, insects, protozoa, viruses, and bacteria. Endoparasites such as hookworms and tapeworms dwell inside the host, while ectoparasites such as ticks and fleas live outside the host. Some insects lay their eggs in plant stalks. When the eggs hatch, the larvae feed and grow inside a gall, which is a tumor-like development on the plant. This is an obligate relationship for the insect; it would be impossible for them to reproduce without it. The plant, on the other hand, is in a facultative relationship and would be better off without the parasite.

Other Examples

In the natural world, there are several examples of symbiotic interactions. Cows, for example, eat a lot of plants high in cellulose fiber despite the fact that their stomachs lack the enzymes needed to break down them. However, symbiotic microbes in their digestive systems break down the cellulose into smaller bits that the animals can digest. Similarly, microorganisms in our digestive tracts are responsible for breaking down dietary waste. Underwater, parasites discovered on other fish nourish specific shrimp and fish species. The symbiotic interaction between people and their agricultural animals can also be witnessed. Farmers provide food, shelter, and protection for their animals in exchange for food and raw materials for clothes.

Five Types of Ecological Relationships

The interactions between and among organisms in their environment are referred to as ecological relationships. The ability of either species to survive and reproduce, or “fitness,” may be influenced by these interactions in one of three ways: positively, negatively, or neutrally. Ecologists have identified five broad forms of species interactions based on how these impacts are classified: predation, competition, mutualism, commensalism, and amensalism.

1. Predation: One Wins, One Loses

Any relationship between two species in which one species gains by taking resources from and to the disadvantage of the other is referred to as predation. While it’s most commonly linked with the conventional predator-prey interaction, in which one species kills and consumes another, not all predation interactions end with one creature dying. In herbivory, a herbivore frequently consumes only a portion of the plant. While this motion may cause damage to the plant, it also has the potential to disperse seeds. In talks of predation, many ecologists include parasitic interactions. The parasite causes harm to the host over time, maybe even death, in such partnerships. Parasitic tapeworms, for example, attach themselves to the intestinal lining of dogs, humans, and other mammals, where they consume partially digested food and deprive the host of nutrients, decreasing the host’s fitness.

2. Competition: The Double Negative

When numerous species compete for the same limited resource, competition occurs. Because one species’ usage of a limited resource reduces its availability to the other, competition reduces both species’ fitness. Interspecific competition occurs between members of different species, while intraspecific competition occurs between individuals of the same species. Georgy Gause, a Russian ecologist, postulated in the 1930s that two species vying for the same limited resource could not coexist in the same location at the same time. As a result, one species may face extinction, or evolution may minimize competition.

3. Mutualism: Everyone Wins

Mutualism is a term used to describe a relationship that benefits both species. The mutualistic association between alga and fungus that forms lichens is a well-known example. The photosynthesizing alga provides nutrition to the fungus in exchange for protection. Lichen can also colonize areas that are unfavorable to either creature on its own. Mutualistic partners cheat in rare cases. Some bees and birds are rewarded with food without having to provide pollination services. These “nectar thieves” gnaw a hole in the flower’s base, avoiding contact with the reproductive components.

4. Commensalism: A Positive/Zero Interaction

Commensalism is a relationship in which one species benefits while the other is unaffected. Cattle egrets and brown-headed cowbirds, for example, forage in close proximity to cattle and horses, eating on insects flushed by the livestock’s activity. This relationship is beneficial to the birds, but it is not beneficial to the animals. It’s often difficult to tell the difference between commensalism and mutualism. The relationship is more accurately defined as mutualistic if the egret or cowbird feeds on ticks or other pests off of the animal’s back.

5. Amensalism: A Negative/Zero Interaction

Amensalism is a type of interaction in which the presence of one species has a negative effect on another but has no effect on the first. A herd of elephants, for example, traveling across a terrain may trample delicate flora. When one species produces a chemical molecule that is damaging to another, amensalistic interactions are widespread. The chemical juglone released by black walnut roots inhibits the growth of other trees and shrubs but has no effect on the walnut tree.

30+ Examples of Mutualism

1. Plant Pollinators and Plants

Pollination of flowering plants is dependent on insects and animals. While receiving nectar or fruit from the plant, the plant-pollinator also collects and transmits pollen.

Pollination of flowering plants is mainly reliant on insects and other creatures. The delicious smells released by flowers attract bees and other insects to plants. When the insects collect nectar, pollen coats their bodies. Pollen is carried from one plant to the next by the insects as they go from one to the next.

2. Ants and Aphids

Some ant species herd aphids to ensure a steady supply of honeydew produced by the aphids. The ants defend the aphids from other insect predators in exchange.

Aphids and other insects that feed on sap are raised by some ant species. The ants herd the aphids with the plant, shielding them from predators and transporting them to excellent sap-gathering places. The ants then use their antennae to stroke the aphids, causing them to create honeydew droplets. The ants benefit from a continual food source, while the aphids benefit from protection and shelter in this symbiotic relationship.

3. Oxpeckers and Grazing Animals

Oxpeckers are birds that feed on ticks, flies, and other insects that are found on cattle and other grazing mammals. The oxpecker gets fed, and the animal it grooms is protected from pests.

Oxpeckers are a type of bird found in Sub-Saharan Africa’s savanna. They are frequently observed perched on buffalo, giraffes, impalas, and other large mammals. They eat insects that are typically found on grazing animals. Tick removal, flea removal, lice removal, and other bug removal is a valuable services because these insects can cause illness and sickness. In addition to removing parasites and pests, oxpeckers will warn the herd of the presence of predators by making a loud warning call. This defense mechanism protects the oxpecker as well as the grazing animals.

4. Clownfish and Sea anemones

Clownfish reside within the sea anemone’s protecting tentacles. In exchange, the sea anemone is cleaned and protected.

Clownfish and sea anemones have a mutualistic connection in which each party benefits the other. In their aquatic surroundings, sea anemones stick to rocks and grab prey by stunning them with their toxic tentacles. Clownfish are poison-resistant and reside within the anemone’s tentacles. Clownfish clean the tentacles of anemones, keeping them parasite-free. They also serve as bait, bringing fish and other animals into striking distance of the anemone. The sea anemone protects the clownfish by keeping possible predators away from its stinging tentacles.

5. Sharks and Remora Fish

Remora are little fish that may attach themselves to sharks and other large sea creatures. The remora are fed, while the shark is groomed.

Mora fish, which can grow to be 1 to 3 feet long, use their specialized front dorsal fins to adhere to passing marine animals such as sharks and whales. Remora provide a valuable service to sharks by keeping their skin parasite-free. Sharks will even let these fish inside their jaws to clear dirt from their teeth. Remora also eat leftover pieces from the shark’s meal, which helps to keep the shark’s immediate habitat clean. This lowers the shark’s exposure to bacteria and other pathogens. In exchange, the remora fish receive free meals and shark protection. Because sharks also offer transportation for remora, the fish can save energy as an added benefit.

6. Lichens

Lichens are the consequence of a symbiotic relationship between fungal and algae or fungi and cyanobacteria. The fungus obtains nutrients from photosynthetic algae or bacteria, while the algae or bacteria acquire food, protection, and stability from the fungus.

Lichens are complex creatures formed by the symbiotic union of fungal and algae or fungi and cyanobacteria. The fungus is the primary partner in this mutualistic connection, which permits lichens to thrive in a variety of biomes. Lichens grow on rocks, trees, and exposed soil in severe conditions such as deserts and tundra. Within the lichen tissue, the fungus creates a safe protective environment for the algae and/or cyanobacteria to develop. The algae or cyanobacteria partner can photosynthesize and hence supplies nutrients to the fungus.

7. Nitrogen-Fixing Bacteria and Legumes

Nitrogen-fixing bacteria exist in bean plant root hairs, where they convert nitrogen to ammonia. The plant grows and develops using ammonia, while the bacteria acquire nutrients and a suitable environment to flourish in.

One species may live within another in some mutualistic symbiotic partnerships. This is true for legumes (such as beans, lentils, and peas) as well as some nitrogen-fixing bacteria. Nitrogen in the atmosphere is a vital gas that must be converted into a useful form before it can be used by plants and animals. Nitrogen fixation is the process of turning nitrogen into ammonia, and it is critical to the nitrogen cycle in the environment.

Rhizobia bacteria can fix nitrogen and dwell in the root nodules (small growths) of legumes. The bacteria produce ammonia, which the plant absorbs and uses to make amino acids, nucleic acids, proteins, and other biological compounds required for development and survival. The plant provides a safe habitat for the bacteria to flourish in as well as necessary nutrients.

8. Humans and Bacteria

Humans and other mammals have bacteria in their intestines and on their bodies. The bacteria are provided with nourishment and a place to live, while their hosts benefit from digestive benefits and are protected from dangerous microorganisms.

Humans and microbes, such as yeast and bacteria, have a mutualistic relationship. Countless bacteria reside on your skin in mutualistic or commensalism relationships (helpful to the bacteria but not to the host). Bacteria that live in mutualistic symbiosis with humans protect humans from pathogenic bacteria by preventing harmful bacteria from invading their skin. The bacteria obtain nutrition and a place to live in exchange.

Some bacteria found in the human digestive system coexist with humans in a mutualistic relationship. These microorganisms help to digest organic substances that might otherwise go undigested. Vitamins and hormone-like substances are also produced by them. These bacteria are vital for the development of a healthy immune system in addition to digesting. The bacteria profit from the collaboration because they have access to resources and a safe environment to flourish.

9. Bullhorn Acacia and Acacia Ants

Acacia ants (Pseudomyrmex ferruginea) and the bullhorn acacia (Vachellia cornigera), also known as the swelled thorn acacia, have a mutualistic relationship. The plant supplies food and shelter for the ants, and the ants protect the plant from predators.

10. Pistol shrimps and gobies

Pistol shrimp are burrowers, creating holes in the sandy seafloor that they often share with gobies. Outside the burrow, the pair remains close, with the shrimp frequently maintaining physical touch by laying its sensitive antennae on the fish.

When the goby detects a potential predator, it seeks cover in the common burrow via chemical cues and bolts. The shrimp, too, relies on tactile and chemical clues to determine when it has to hide. When the goby is active, it tells the shrimp that it is safe to leave the burrow. Shrimps are also supposed to benefit from their association with the fish by gaining access to more food, such as the fish’s waste or any parasites on its body.

11. Woolly bats and pitcher plants

Pitcher plants are predators that entice insects and tiny vertebrates with nectar around the rim of their tube-like structure. These critters fall into the digestive juices contained in the plant’s equivalent of a stomach due to a slick substance around the rim.

While you may believe that animals would avoid these plants if they could, some bats choose to actively enter them.

Woolly bats have been observed roosting in the tropical pitcher plant Nepenthes hemsleyana, which may be found in Borneo.

While the bat has a safe place to rest, the plant benefits by capturing the guano (feces) produced by the small mammal. This gives the plant the nutrients it requires to thrive.

12. Coral and algae

Corals may resemble rocks or plants, but they are truly sea creatures. Reef-building corals get their vibrant hues from the zooxanthellae algae with which they have a mutualistic connection.

Coral begins as a little, free-swimming larva that eventually attaches to a hard surface and transforms into a polyp. By creating several identical polyps, growing one on top of the other and secreting a rigid skeleton around itself, the polyp duplicates and grows to form a colony.

Corals pick up zooxanthellae from their surroundings as they develop. The coral offers shelter and nutrition for the zooxanthellae to use during photosynthesis, while the zooxanthellae create synthesized sugars, which the coral consumes, as well as oxygen as a by-product.

13. Spider crab and algae 

Spider crabs live in the ocean and spend much of their time in the shallowest parts of the sea, making them highly apparent to predators. Algae, on the other hand, live on their backs and act as camouflage.

  • Algae now have a place to call home.
  • Predators can’t see the spider crab since it’s camouflaged.

14. Flowers and bees 

Flowers and bees also have a mutualistic relationship. Traveling between flowers is how bees collect the nectar they need to make honey. Pollination occurs when a bee transports pollen from one plant to another.

  • Getting food is beneficial to the bee.
  • Pollination is beneficial to the plants.

15. Humans and plants


It is a well-known fact that plants and humans are inextricably linked. This reciprocal relationship is based on the following:

  • Humans inhale carbon dioxide and use the oxygen that plants produce.
  • Carbon dioxide is used by plants to produce the oxygen that humans require.

16. Ants and Fungus

Leaf-cutter ants in their fungus garden.

Ants actively produce fungus, sometimes with the help of leaves and their own feces. The ants eat the fungus as it grows to keep themselves alive.

  • The ant is the one who gives life to the fungus.
  • The fungus is food for the ant, so it’s a win-win situation.

17. Porcelain Crab and Anemone

Under the sea, the sea anemone appears to be a sought-after spouse. Porcelain crabs, it turns out, have a mutualistic relationship with sea anemones. If you come across an anemone that doesn’t have any clownfish in it, take a closer look; you might just find a porcelain crab hidden within its tentacles.

Porcelain crabs, like clownfish, make their home in anemones. The porcelain crab is safe from predators since the anemone stings most water creatures. The anemone enjoys the porcelain crab’s supper crumbs in exchange.

18. Pom-Pom Crab and Anemone 

Another example of mutualism in the ocean is pom-pom crabs, who received their name from clutching anemones on their claws! Yes, they really resemble miniature cheerleaders beneath the waves.

These little crustaceans are also known as boxer crabs because they wander around with anemones on their pincers, much like boxing gloves. The boxer crab may fend off attackers by punching them with a stinging anemone wrapped around its claws.

In exchange, the anemone is given a free ride throughout the reef, feeding wherever the crab goes. The sea anemone enjoys any remaining food from the pom-pom crab.

19. Decorator Crab and Sea Sponge

The decorator crab, which utilizes sponges to paint its shell, is another example of mutualism in the ocean. The decorator crab earned its name from its habit of attaching immobile creatures and plants to its body.

Decorator crabs can evade predators by camouflaging themselves with other marine animals such as sea sponges. In exchange, the sea sponge is able to expose itself to different feeding opportunities based on the crab’s motions.

20. Corals and Zooxanthellae

Zooxanthellae give corals photosynthesis-derived food, and coral polyps offer microscopic plant cells a safe habitat and nutrients to carry out photosynthesis. The corals produce carbon dioxide and water as byproducts, which the zooxanthellae need for photosynthesis.

This two-species symbiosis is one of the most important mutualistic partnerships in the ocean. When ocean temperatures rise, corals are stressed and algae are released from their protected habitat. Coral bleaching will occur if this occurs.

21. Tree roots and fungi

By infecting the plant root, a huge number of fungi develop a mycorrhizal relationship with it. This relationship is distinct from the common root infection that causes root rot.

Mycorrhiza, on the other hand, is not a disease-causing relationship. Instead, the fungus invades the root to extract nutrients, resulting in a mutualistic kind of parasitism. Although this interaction benefits both the plant and the fungus, the majority of land plants rely on mycorrhizal fungi for mineral fertilizers such as phosphorus. As a result, fungus receives nutrients produced by the plant.

Some plants produce few or no nutrients throughout the winter, relying on fungi for nitrogenous compounds, carbohydrates, and other nutrients that the fungi extract from waste products in the soil. The host plants are kept alive because the fungi share these ingested compounds with them.

22. Zebra and Wildebeest

During long-distance migration, the Zebra (Equus burchelli) and the Wildebeest (Connochaetes taurinus) can form a mutualistic relationship. During this time, they collaborate as a technique to thwart predators.

23. Intestinal flagellated Protozoans and Termites

Termites and intestinal flagellated protozoans have a mutualistic interaction. Mutualism in this form is required. However, the protozoans and termites have a close relationship in which the protozoans decompose the wood that the termites consume. As a result, neither the protozoan nor the termites can thrive in the wild without the other.

24. Yucca moths (Tegeticula) and Yucca plants (Yucca)

The yucca plant and the yucca moth have a mutualistic relationship. Yucca moths are reliant on yucca plants. The yucca moth functions as a pollinator on the yucca plant’s flower. It lays its eggs in the yucca plant’s seedpods. Its larvae hatch and eventually feed on some yucca plant seeds. They both gain because the plant gets pollinated and the moth obtains a food source for its larvae.

25. Anemones and Hermit crab

The anemones use the hermit crab’s shell as a secure haven. In exchange, the anemone stings predators to protect the animal.

26. Humans and cohabitants

Modern human communities are being constructed to be more environmentally friendly. Healthier cities are being developed with the goal of creating harmony with other animals that share the same habitat. Such towns are conceived and created with the goal of balancing human health and ecological life with nature in mind.

27. Fig wasp and Fig trees

A mutualistic relationship exists between the fig wasp and the fig tree. Their mutualism is required since their life cycles are intertwined. The queen fig wasp enters the fig through an aperture, where she loses her antennae and wings. The flower and seed cluster is contained within the figure. She lays her eggs inside the fig tree and also deposits pollen from another fig tree. As a result, the fig’s ovaries are fertilized.

28. Cow and bacteria

Rumen bacteria exist in cows and have a mutual interaction with them. These bacteria live in the cow’s digestive system and aid in the digestion of the plants that the cow consumes.

They have difficulty digesting the cellulose found in plants. So the bacteria in cows’ rumens aid in digestion, and in exchange, the bacteria receive food and the warm environment required for growth and development.

29. Bats and Fig Trees

Both species benefit from the synergistic relationship between bats and fig trees, hence it is mutualistic. Fruit bats aid in the propagation of fig seeds by ingesting the seeds with the flesh of the figs and dispersing them when bats excrete waste products.

30. Honey Bees and Plants

Honey bees travel to a wide variety of plant species to collect nectar from flowers. As a result, these plants are visited by a high number of other insects that serve as pollinators. Honey bees are responsible for pollination.

Lesson from Mutualism

Darwinian themes have been applied to company strategy over the past 200 years. For numerous generations of CEOs, “Survival of the Fittest” encapsulated both the incentive system and business spirit. As a result, business clichés such as “playing to win,” “smart growth,” “dog-eat-dog world,” and “winners and losers,” to mention a few, have gained traction over the decades.

When we look at nature, we can see that these corporate doctrines are predatory and parasitic, despite their misleading banality. One’s growth comes at the expense of another’s. All natural systems, including our planet, would have long since imploded in self-destruction if all natural connections were of this sort.

Darwin’s theories have been oversimplified, omitting the element of mutualism—a powerful concept from nature of shared growth that all organizations can draw inspiration from as they evolve their strategic approaches. This is a once-in-a-lifetime opportunity. New potentials for corporations and countries can be unlocked if they are studied and leveraged.

Mutualism is an important aspect of ecology that has gotten less attention in the past than other interactions like predation and parasitism. More than 48 percent of land plants rely on mycorrhizal partnerships with fungi to feed them with inorganic compounds and trace elements, making mutualistic interactions critical for terrestrial ecosystem functioning. Another example is the estimated 70-90 percent of tropical forest plants with deep distribution mutualisms with mammals.

If we look to nature for an explanation of parasitic growth, we can see that if the physical growth of a system/species does not reach an optimum size in terms of the resources and life-support system on which it depends, cancerous growth— is uncoordinated and uncontrolled parasitic growth that becomes lethal when it can no longer be supported by the system on which it depends—will become increasingly threatened.

Analysts, economists, and journalists refer to parasitic corporations as those that do not account for externalities. They are unconcerned with the welfare of their employees. They don’t consider the larger community or supply chain members. They are unconcerned about the effects of their actions on the environment. Unfortunately, in today’s economy, far too many businesses meet this criterion.

After pure physical growth becomes undesirable or unattainable in nature and for human existence, the focus should shift to expanding the growth of human existence’s quality and supporting systems.

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