5 Examples of commensalism

Commensalism is a form of interaction between species in which one species benefits without having a significant impact on other species. Here are five examples of commensalism:

  1. Birds over Farm Animals:
  • Insect-eating birds are often found on livestock such as cows or buffalo. These birds benefit from eating insects that live on the skin of livestock without having a significant negative impact on the animals.
  1. Remora Fish and Shark:
  • The remora fish attaches itself to the body of a shark or other large marine animal using its special suction device. Remora fish benefit from the movement of these animals and food waste produced by sharks, while sharks do not receive a significant impact from the presence of remora fish.
  1. Epiphytes in Tropical Trees:
  • Several types of epiphytic plants, such as bromeliads or moss, live attached to the trunk or branches of tropical trees without harming the tree. Epiphytic plants benefit from high places and sunlight, while trees provide a comfortable place for these epiphytic plants.
  1. Horses and Certain Birds:
  • Occasionally, small birds are found sitting or standing on the backs of horses or other large animals. These birds benefit from having a better view to find food or observe their surroundings, while horses are less affected by the presence of these birds.
  1. Butterflies and Other Insects Around Flowers:
  • Butterflies and other insects often feed on nectar around plant flowers. Apart from getting food from nectar, butterflies also help in the process of pollinating plants without having a significant negative impact on the plants.

All of the examples above illustrate relationships in which one species benefits without causing significant harm to the other species in the relationship.


In the vast web of interactions within ecosystems, there exists a fascinating ecological phenomenon known as commensalism. Derived from the Latin word “commensalis,” meaning “sharing a table,” commensalism refers to a symbiotic relationship between two species where one benefits while the other remains unaffected. In this article, we will explore the concept of commensalism, its various examples, and the significance of this unique relationship in the natural world.

Understanding Commensalism:

Commensalism is a type of symbiotic relationship that occurs when one organism benefits from the association, while the other organism is neither harmed nor benefited. This means that one species takes advantage of the presence or activities of another species without causing any harm or benefit to the latter.

Examples of Commensalism:

  • 1. Remora and Sharks: Remoras, also known as suckerfish, have a unique relationship with sharks. They have a modified dorsal fin that acts as a suction cup, allowing them to attach themselves to sharks. By hitching a ride, remoras can benefit from the shark’s movement, gaining easy access to food scraps and protection from potential predators. The sharks, on the other hand, are not affected by the presence of the remoras.
  • 2. Orchids and Trees: Epiphytic orchids are plants that grow on the branches or trunks of trees. These orchids do not harm the trees or take nutrients directly from them. Instead, they use the trees as a structure to grow upon, gaining access to sunlight and moisture in the tree’s canopy. The trees receive no apparent benefit or harm from the presence of the orchids.
  • 3. Cattle Egrets and Grazing Animals: Cattle egrets are birds that often accompany grazing animals, such as cattle or buffalo. As the grazing animals move through grassy areas, they disturb insects, making them easier for the egrets to catch and feed upon. The egrets benefit from the insects flushed out by the grazing animals, while the animals are unaffected by the presence of the birds.

Significance of Commensalism:

  • 1. Utilization of Resources: Commensalism allows certain species to take advantage of available resources without expending much energy. By associating with other species, they can access food, shelter, or transportation that would otherwise be challenging to obtain.
  • 2. Biodiversity: Commensalism contributes to biodiversity by creating intricate ecological relationships. The presence of commensal organisms adds complexity to ecosystems, enhancing the overall stability and resilience of the natural environment.
  • 3. Evolutionary Adaptations: Commensalism can drive evolutionary adaptations in species. Over time, the species involved in commensal relationships may develop specialized structures or behaviors that optimize their interactions with their partners, increasing their chances of survival and reproduction.


Commensalism represents a fascinating ecological relationship in which one species benefits while the other remains unaffected. Examples such as the remora and sharks, orchids and trees, and cattle egrets and grazing animals demonstrate the diverse ways in which commensalism manifests in nature. This unique relationship allows species to utilize available resources, contributes to biodiversity, and drives evolutionary adaptations. By studying and appreciating commensalism, we gain a deeper understanding of the intricate balance and interdependence of species within ecosystems, highlighting the wonders and complexity of the natural world.