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commensalism

American  
[kuh-men-suh-liz-uhm] / kəˈmɛn səˌlɪz əm /

noun

  1. Ecology. a type of relationship between two species of a plant, animal, fungus, etc., in which one lives with, on, or in another without damage to either.

  2. Sociology. peaceful coexistence among individuals or groups having independent or different values or customs.


commensalism Scientific  
/ kə-mĕnsə-lĭz′əm /
  1. A symbiotic relationship between two organisms of different species in which one organism derives benefit while the other is unaffected. Examples of commensalism include epiphytic plants, which depend on a larger host plant for support but which do not derive any nourishment from it, and remoras, which attach themselves to sharks and feed on their leavings without appreciably hindering their hosts.

  2. Compare amensalism mutualism parasitism


Usage

What does commensalism mean? Commensalism is a relationship between two species of organisms, such as plants, animals, and fungus, in which one species benefits while the other is unaffected, as in Scientists have studied the commensalism of fleas that feed on birds’ feathers. A well-known example of commensalism is the relationship between the remora, commonly known as a suckerfish, and a shark. The  remora uses its suction cup–like head to attach itself to a shark. The remora benefits from the speed, protection, and leftover food from the shark. The shark gets nothing from the remora. It isn’t hurt by the remora, but the remora doesn’t help the shark in any way. You can think of commensalism as a “+/0” relationship: One species benefits while the other remains the same. This is what sets commensalism apart from the other types of relationships between organisms, such as mutualism, parasitism, and amensalism. In mutualism, both species benefit from the relationship. For example, a bird might pick food out of the teeth of an alligator, which prevents the teeth from becoming infected. Mutualism is a “+/+” relationship because the bird gets food to eat and the alligator gets cleaner teeth. In parasitism, one species (the parasite) benefits at the expense of the other species, a “+/-” relationship. For example, when a  mosquito bites you, it has drunk some of your blood, which nourishes it. You, however, get an itch bite and possibly a disease carried by mosquitoes, such as Eastern equine encephalitis (EEE). In amensalism, one species harms another species while remaining unaffected, a “-/0” relationship. For example, the black walnut tree secretes a substance that is harmful to other plants. The tree isn’t harmed by either the substance or the other plants.

Etymology

Origin of commensalism

commensal + -ism

Compare meaning

How does commensalism compare to similar and commonly confused words? Explore the most common comparisons:

Explanation

If you've ever seen a bunch of barnacles attached to a great big whale, you've seen an example of commensalism, or one organism getting benefits from another without hurting it. First used in a biological sense in 1870, commensalism originates from the Middle Latin word commensalis, derived from com ("together") and mensa ("table"). It's a relationship between two organisms in which one receives benefits without causing harm. Commensalism should not be confused with mutualism, a relationship in which both organisms benefit from each other.

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Vocabulary lists containing commensalism

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Commensalism is a symbiotic relationship in which one organism benefits and the other is neither helped nor harmed.

From Textbooks • Jan. 1, 2018

Commensalism occurs when one member benefits without affecting the other.

From Textbooks • Jan. 1, 2015

Commensalism: applied to this manner of living and eating together.

From Explanation of Terms Used in Entomology by Smith, John. B.

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