11+ Commensal Examples: Detailed Facts

This article would highlight a series of commensal examples with detailed facts in order to gain an in-depth understanding about the symbiotic relationship commensalism. 

Commensalism is described as the symbiotic relationship between two species where one of them is benefitted while the other remains unharmed or unbothered. The species that benefited from the association is called commensal whereas the other unharmed species is termed as the host species.  

Commensal examples: Protozoa 

In the human intestinal tract, there are traces of nonpathogenic intestinal protozoa. These are single-celled parasites which do not associate themselves with any form of illness being caused to humans. These do not affect the human body even if they have a compromised or weak immune system. 

The species which are commonly found in the intestinal tract of the human beings without causing any harm are Chilomastix mesnili, Endolimax nana and more which serves as effective commensal examples. 

Another commensal example would be the amoeba Entamoeba coli, which is in endo-commensal with humans and feeds on the bacteria present in the lumen of the intestine. Then there is the presence ciliate protozoan Ephelota gemmipara, which is an ectocommensal on different types of marine invertebrates.

Commensal examples: Bacteria 

Commensal bacteria engage in supplying the host with beneficial nutrients and also defend the host against a series of opportunistic pathogens. These commensal bacteria are important in developing intestinal architecture along with immunomodulatory processes. The host on the other hand engages in providing the bacteria with essential nutrients to support the growth and ensure a favourable environment. 

Oral commensals

In the human body, there are oral commensals, namely Streptococcus oralis and Streptococcus salivarius, which involves in protecting the middle ear from inflammation, identified as the term otitis media which is caused by the pathogens namely S. pneumoniae and Haemophilus influenzae.

Skin Commensals

Another commensal example would be of Corynebacterium accolens, which is present on the skin of the human body and encodes lipase in order to catalyse the hydrolysis process of host triacylglycerols in order to produce free fatty acids which has antibacterial properties that has the ability to suppress the growth of S. pneumoniae. 

Commensal Examples: Flora and Fauna 

Few of the commensal examples in terms of flora and fauna within the ecosystem are as follows: 

Emperor Shrimp and sea cucumbers 

The emperor shrimp falls under the category crustacean and are found commonly in the Indo-pacific region. These are found attached to sea cucumbers in order to facilitate transportation as well as protection from various predators. 

This saves the emperor shrimp from spending unnecessary energy. Since the emperor shrimp is small in size, it does not affect the sea cucumbers in their movement. 

Caribou And Arctic Fox

The arctic fox helps to trail the caribou when the reindeers prowl for their food. The fox digs up soil which leads to the exposure of the lichen plants. This attracts the subnivean mammals to the site while the fox maintains distance to avoid being preyed on by the reindeers. 

Burdock Seeds On Animals

There are several plants with evolved dispersal features, which includes the curved spines. Burdock plants are situated mostly along the sides of the roads. The seeds of these plants have long and curved spines which is helpful in getting attached to the fur of the animals. 

This helps in further transportation of the seeds in various areas. The seeds are so light that the pressure is not recognised by the animals. 

Barnacles and whales 

Barnacles fall under the category of crustaceans and do not have the ability to move on their own. During the larval stage, barnacles tend to attach to other organisms like whales. Further growth occurs on the whales without affecting it negatively.

Barnacles further feed on various plankton along with other food materials as the whale engages in moving. Hence, it benefits barnacles in both nutrition and transportation without affecting the whale. 

Army Ants and birds 

The commensal relationship between army ants and birds has been identified to be unusual as both the species can prey on the other. 

The birds engage in trailing with the ants to feed on the various insects that would escape from the ants as they move through the forest. This helps the birds to catch easy prey while not affecting the ants. 

Pseudoscorpions and beetles

Pseudoscorpions are small insects that look like scorpions and lack stingers. It tends to hide on the surfaces which are exposed onto the host animals. The host animals are either fur-based animals or the bees or beetles with wings. 

Pseudoscorpions tend to gain transportation along with protection from various predators. Pseudoscorpions are so small that it does not cause any harm to the host insects like the beatles or bees. 

Sharks And Remora Fish

The remora fish are small in size and are the member of ray-finned fish. It has special suckers that can easily get attached to large organisms like sharks or whales. 

This helps the remora fish in transportation and even extends protection from various marine predators. The small size does not affect the large shark or whales. 

commensal examples
Commensal Example: Shark and Remora from Flickr

Commensal Symbiotic Relationship types with examples 

There are various types of commensal symbiotic relationships which are as follows with commensal examples: 


In inquilinism, one of the species engages in using another species regarding permanent housing. 

Example: The birds that live by making holes in the trees like woodpeckers. 


Metabiosis is described as a commensalistic relationship where one of the species engages in forming habitat for the other species. 

Example: The hermit crab utilises the shells of dead gastropods in order to manage its own protection. 


In phoresy, one of the species would engage in attaching to another species to facilitate transportation. 

Example: one is the attachment of anemone on the top of hermit crab shells. Another would be pseudoscorpions that live on mammals. 


Microbiota are identified as commensal organisms that engage in forming communities with the host organisms. 

Example: Bacterial flora that are found naturally on the top layer of the skin in humans.

Sayantani Misra

Hi, I am Sayantani Mishra, a science enthusiast trying to cope with the pace of scientific developments with a master’s degree in Biotechnology. Let's connect through LinkedIn-https://www.linkedin.com/mwlite/in/sayantani-misra-a54a83200

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