Commensalism is a type of biological interaction.
Commensalism is a type of interaction that occurs in biology , where one of the parties obtains some benefit and the other is not favored, but is not harmed either. The concept comes from the Latin expression com mensa , which can be translated as "sharing a table."
The original use of the term, therefore, is linked to the relationship that arises when scavengers chase game species to eat the leftovers left by them. The first group, in short, takes advantage of the surplus resources of the second population.
Examples of commensalism
A clear example of commensalism based on this meaning and explanation is the one established between lions and vultures that live in a specific area. Thus, what the aforementioned scavenger birds do is feed on the remains of the bodies of animals that are killed and devoured by the aforementioned felines.
However, when talking about this type of relationship between animal species, it is common to use as an example the one established between sharks and remoras . The latter are fish that have a suction cup on their upper extremity and this is what they use to adhere to the bodies of the sharks themselves, which do not notice their presence at all. In this way, these remoras feed on their food remains.
In a commensalism relationship, one party benefits and the other is neither benefited nor harmed.
Tenancy and phoresis
Another type of commensalism is inquilinism . This relationship involves one organism hosting another, like the woodpecker that holes trees for shelter.
Among the most common examples of tenant farming is the one that occurs in field mouse burrows. Spaces where, in addition to these rodents, insects of various types also live. They feed on the roots that grow there and on the waste left over from the food that the owners of these "homes" eat.
Phoresis , on the other hand, is the use of a second living being as a means of transportation. An example of this type of commensalism occurs with fish that ride on a shark.
Other types of commensalism
In the case of metabiosis (also known as tanotocresia ), the link between both organisms is indirect, since one uses something from the other but only after the death of the organism in question, such as the hermit crab that uses the snail shell as protection. .
It should be noted that there are other biological interactions beyond commensalism. In this sense, one can speak of parasitism (with an organism that increases its reproductive fitness by detriment to the reproductive fitness of another) or mutualism (a link where both species increase their biological fitness).
In the same way we also have to make special mention of what is known as amensalism . In this case, the relationship that occurs between two living beings is disproportionate since one of them is harmed in this interaction while the other is not affected at all. This would be the case, for example, of those trees that prevent sunlight from reaching the herbs that grow next to them.
Symbiosis , finally, is a special kind of mutualism, with a close and extended relationship between organisms of different species.