Commensalism

Definition

Commensalism is a type of symbiotic relationship where one organism benefits while the other is neither helped nor harmed. In fungal biology, this often involves fungi living on or within a host organism without causing it any harm.

5 Must Know Facts For Your Next Test

1. Commensalism involves an interaction where only one organism benefits while the other remains unaffected.
2. In fungi, commensal relationships can be seen with certain species that live on human skin or within other organisms without causing disease.
3. Unlike parasitism, commensal fungi do not harm their hosts and may even provide some indirect benefits, such as occupying space that might otherwise be taken by harmful pathogens.
4. Examples of commensal fungi include some yeast species found in the human microbiome.
5. Understanding commensal relationships in fungi helps differentiate between harmless and pathogenic interactions.

Review Questions

• What distinguishes commensalism from parasitism in terms of the impact on the host?
• Can you name an example of a commensal fungus and describe its typical habitat?
• How might commensal fungi indirectly benefit their host organisms?

Related terms

Parasitism:

A symbiotic relationship where one organism benefits at the expense of another.

Mutualism:

A symbiotic relationship where both organisms involved benefit from the interaction.

Mycorrhizae: Symbiotic associations between fungi and plant roots that are often mutualistic but can have varying degrees of benefit.