Commensalism: Definition, Examples, Facts, Topics, Relationships

What Is Commensalism?

Commensalism is a kind of symbiosis where one organism gains or is favoured and the other is unaffected or has no advantage or disadvantage. In commensalism, the organism that gains an advantage, often in the form of food, shelter or transportation has no negative impact on the host organism or may even offer some minor service to the host organism. This invites a clear difference from mutualism, where both organisms benefit; parasitism where the predator benefits and the defend gains nothing; and amensalism where the defended gains is harmed but the defender is unharmed.

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1. What Is Commensalism?
2. Types Of Commensalism
3. Examples Of Commensalism In Different Ecosystems
4. Recommended video for Commensalism
5. Case Studies

Some examples of commensal relationships are the barnacles that stick on the whales for transport without affecting the whales in any way, the epiphytes that grow on trees while at the same time not affecting it, some bacteria that just reside on the human skin without in any way being parasitic. Commensalism teaches people that the level of interdependence in the natural world is not rigid and that the influence two species can have on each other can be significantly different.

Types Of Commensalism

The types of commensalism is described below-

Inquilinism

Inquilinism, where one organism occupies the home of another organism and does not benefit or harm the host organism is the third type of parasitism.

Examples: Sessile animals live on other animals, for example, barnacles are crustose animals that attach themselves to a larger animal, a ship for instance, and derive their nutrition from the surroundings without harming the host. Barnacles are parasites which affix themselves to a whale or other sea creature and rely on it for mobility and feeding rights but do not harm the host.

Phoresy

Phoresy is one of the types of mutualistic relations where one species utilizes the other to get from one place to another.

Examples: Microorganisms change locations by moving from one place to another on insects or small animals or from one food plant to another. Remoras anchor themselves to sharks or large fish and feed off what is attracted by the motion of the host and pieces of food disturbed by the creature.

Microbiota

Microbiota involves microorganisms that are present on or within larger animals but do not harm the animal.

Examples: The stomach and intestinal bacteria are involved in the process of digesting feed and synthesizing useful products with the help of available nutrients within the host organism. Skin microbial communities encompass bacteria and fungi that live on the skin they act as anti-pathogens and play a role in skin health.

Examples Of Commensalism In Different Ecosystems

The examples are listed below-

Terrestrial Ecosystems

Birds and trees

Some species have the ability to make a tree their home without damaging that tree in the process; they make their nests in trees. It offers a firm base and a source of shelter for the birds and a place where they can lay eggs.

Epiphytes on rainforest trees

The vertical space is characterized by smaller plants that do not need to be rooted in the earth; they live on the trees and obtain both support and light: orchids, bromeliads, ferns and others. Epiphytes do not damage the host trees and may be beneficial to the host by helping to retain moisture.

Marine Ecosystems

Barnacles on whales

Barnacles must adhere to large animals such as whales, and feed with the help of the host’s activity and water rich in nutrients. Barnacles have very little impact on the bodies of the whales and minor skin irritation may occur only when the whales’ skin is heavily infested.

Clownfish and sea anemones

Clownfish form Allies with sea anemones because they cannot be attacked by any predator because of the stinging elements on the tentacles of the sea anemones, in return the sea anemones benefit from feeding on the foods that are brought to them by these clownfish, and the cleaning of the tentacles.

Human Body

Skin flora

Skin microbiota or skin flora is the microorganisms that are present on the human skin which includes bacteria, fungi and many more. The favourable type of bacteria also originates on the skin and helps counterbalance pathogenic microorganisms in terms of habitat and nutrition, thus protecting the skin from infections.

Gut microbiota

Gut microbiota refers to a composition of bacteria and other microorganisms that reside in the human gut and their number approximates trillions. As such, these microorganisms help in digestion, production of vitamins, and the immune system regulation. In turn, they get to support a generally healthy nutrient environment of the gut.

Recommended video for Commensalism

Case Studies

The case studies are explained below-

The Oxpecker And Large Herbivores

Historical views: Mutualism vs. Commensalism

Early, it remains on the verge of mutualism and commensalism between the two, with oxpeckers benefiting from feeding on the large herbivores’ skin especially to remove the ticks and parasites that may be infesting the skin, and at the same time, the oxpecker would sometimes peck on the blood oozing from the wounds on the large herbivore.

Recent studies and findings

Newer studies have established that the association is complex; hence, oxpeckers mainly help herbivores by removing ectoparasites but sometimes harm them slightly. Such dynamics clearly illustrate the presence of more positive than negative interactions with the hosts, which are rather reciprocal and depend on the hosts’ and environmental conditions.

Human Gut Microbiota

Role in human health

The human gut microbiome is trillions of microorganisms which help in digestion, synthesis of vitamins, and immune responses. Imbalances in the composition of the bacterial communities living in the gut resulting from multiple factors – the diet in particular, or taking antibiotics, can cause diseases like inflammation and metabolic disorders.

Balance between commensalism and pathogenicity

The field of commensalism and pathogenicity is based on the observation made by researchers that some microorganisms are capable of living with their host in a mutually non-harmful manner as commensalism while at the same time being capable of being pathogens under certain circumstances. This knowledge is essential in assessing the health hazards and sustaining the control of microbes in environments and, at the same time, in people’s anatomies.