Teaching Students About Commensalistic Relationships

As educators, it is our responsibility to teach our students about the various relationships that exist in the environment. One such relationship is commensalism. This relationship is often overshadowed by its more popular counterparts – mutualism and parasitism – but it is no less important. Commensalism is a type of symbiotic relationship where one organism benefits from the presence of another, but the second organism is neither harmed nor helped. In this article, we will explore how to teach students about commensalistic relationships.

  1. Define commensalism:

Begin the lesson by defining commensalism and how it works. Explain to students that commensalism is a symbiotic relationship where one organism benefits from the presence of another, but the other is unaffected. This concept can be illustrated by using examples of organisms like barnacles that cling to whales or birds nesting in trees.

  1. Identify organisms:

Next, identify organisms that exhibit commensalism in the natural world. There are numerous examples of commensalistic relationships, and some of the most common include:

– Remoras that attach themselves to sharks for transportation and feeding opportunities.

– Epiphytes that grow on the surface of trees, taking advantage of the nutrients and support offered by the tree.

– Hermit crabs that use empty seashells as a safe hiding place.

You can also ask students to conduct research and find additional examples of commensalism.

  1. Teach the significance:

Once students understand the concept and have identified examples, it is important to explain why these relationships are significant. Point out how commensalism is essential for the functioning of ecosystems. For example, epiphytes can regulate the temperature and humidity around the tree canopy, which helps to create a microclimate for the animals living in the area.

  1. Encourage critical thinking:

Encourage students to think critically about commensalism by asking open-ended questions. For instance, ask students to speculate on what would happen if one organism in a commensalistic relationship disappeared. Would the other organism be able to survive without it? Or would the relationship cease to exist?

  1. Real-life applications:

Finally, introduce real-life applications of commensalism. For instance, ask students to ponder why airline companies offer frequent flyer programs. This is an example of commensalism because the airlines benefit from customers’ frequent travelling, while the customers receive incentives like free flights and reward points. This analogy can help students understand how commensalism occurs even in our society.


Teaching students about commensalism is essential for their understanding of the natural world. By providing examples and encouraging critical thinking, we can help our students appreciate the significance of these symbiotic relationships. Moreover, a deeper awareness of commensalism in the environment can foster understanding, care, and respect for nature and its connection with humans.

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