Mutualism: Definition, Types and Examples

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What is Mutualism?

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The definition of mutualism is given as a relationship where both the species are equally mutually benefited. The connection can be within the species itself or between two species. The term, ‘symbionts’ is used for the species with this relationship. Mutual relationship is a common occurrence among all living organisms like human beings, plants, and animals. Other microorganisms such as bacteria, fungi are also not devoid of it. Mutualism can also be depicted as one sort of symbiosis. 

Mutualism is a type of relationship that occurs between the host and the symbiont. Here both the organisms get an advantage, with hardly any harm being caused to them. The relationship span can be long or short-lived. The small partner is known as the ‘mutualist’, and other partners present in the Mutualism, are the hosts. 

Example of Mutualism

Let us consider the bees and the flowers. The bees fly from this flower to the other and collect nectar, to make food and thus benefit themselves. From the flowers, the bees get pollen that pollinates the next flower the bees sit on, thus benefiting the plant. Therefore, through this mutualistic relationship, the bees get their food and the plants can reproduce. 

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Types of Mutualism 

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There are five types of mutualism that are discussed below in detail:

Obligate Mutualism 

Obligate Mutualism is the relationship between two species where both of them are dependent on each other. Maximum of the symbioses and some non-symbiotics correctly set the examples of Obligate mutualism. 

• Let us consider the example of the relationship between ants and acacia plants here. The plant is responsible for sheltering the ant and providing it with food.
• In return, the ants protect the plant from external enemies such as other herbivores and organisms, preventing them from eating the plant. Also, the ants clear up other plants from the domain, to help in the steady growth of their home plant. 

• To cite another example, we can talk about the mycorrhizal fungi, thriving on the plant roots. The plants get the advantage of the escalated water uptake from the fungi whereas the fungi can draw nutrients from the plant. 

Facultative Mutualism 

Facultative mutualism is defined as an important type of mutualism that involves coexisting of the partners without depending on each other. A diffuse relationship is formed, initiating a different mixture of species. 

• We have already spoken about the bees and plant relationship. This is the most significant example to describe Facultative Mutualism.
• The bees visit different plants to gather the nectar. Again, the plants are approached by many insects as pollinators to help the plants in pollination. 

Trophic Mutualism (Resource to resource benefit)

In trophic mutualism, the partners are particularized through compatible ways to derive energy and nutrients from each other. Trophic mutualism is an ecological interaction, involving resource to resource interlinkage, to transfer energy and nutrients between two species. This type of mutualism is found between two different trophic levels such as heterotrophs and autotrophs. 

Defensive Mutualism (Service to Service Benefit)

Defensive Mutualism is the relationship between two, where one partner gets food and shelter and protects the other from parasites or any outer combatants such as predators. 

Example : The relationship between the ants and acacia plants once again relates here. The plant protects the ant with shelter and food whereas the ants protect the plants from any outward adversaries. 

Dispersive Mutualism (Resource to Service benefit)

Dispersive mutualism is the relationship, where one partner gets food as a return after helping the flowers to relocate their pollens. The process includes angiosperms and insects or bees and wasps. 

• The insects are the resource recipients, i.e., they acquire food in the form of nectar from the flowering plants.
• On the other hand, plants are benefitted as the insects perform pollination, helping the plants to reproduce. 

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Detailed Examples of Mutualism 

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Now, we will be discussing in detail some important examples of Mutualism. 

Humans and Plants 

Oxygen is the essential component for human beings to exist. Similarly, plants need Carbon-di-oxide to live and carry out photosynthesis. Humans intake the oxygen provided by the plants, whereas the plants use the carbon-di-oxide, blown out by the humans. 

Cow and Bacteria 

The cow and the bacteria bear a symbiotic relationship. The cow is responsible for providing the bacteria with a decent and warm environment and food to live in. The food supply is constant. Again, the bacteria help the cow to retrieve nutrients in its diet that are enriched with cellulose, thus initiating a source of protein. 

Oxpeckers and Rhinos 

Oxpecker is a bird that thrives on the body of the Rhino. All the parasites from the animal body are removed by parasites. For this, oxpecker is rewarded with food from the Rhino. This shows the mutual relationship between oxpeckers and rhino that how both the bird and the Rhino are benefitted with no harm.