We explain what commensalism is and its differences with mutualism. Also, examples and how it develops in the desert.
What is commensalism?
Commensalism is known as a specific type of interspecific biological interaction, that is, interaction between individuals of different species , characterized by the benefit of only one of those involved , without the other party receiving any type of harm or harm.
The term commensalism comes from the Latin cum mensa, which translates as “sharing the table” , and was originally used for those cases in which one animal fed on the remains of another’s food, as do scavengers , which wait for food. for the hunter to finish feeding. However, there are many other cases that can be understood as commensalism, such as:
- It occurs when the commensal uses another species to transport itself from one place to another.
- In this case, the commensal finds lodging in the member of the other species.
- Metabiosis or thanatocrisia. The diner takes advantage of the excrement, remains or corpses of another species to protect itself, reproduce or help itself in some way.
It can help you: Interspecific relationships
commensalism and mutualism
Some fungi live between the roots of certain trees exchanging nutrients.
Unlike commensalism, in which only one species involved benefits, in the case of mutualism, both species benefit from their interaction . This type of case is typical between species that present mutually compatible biological characteristics, being able to provide positive feedback, that is, mutual benefit.
This is the case, to cite an example, of mycorrhizae: fungi that live among the roots of certain trees, exchanging nutrients and organic matter (used by the fungus) with them in exchange for water (usable by the tree roots). Both organizations benefit.
Continue on: Mutualism
Examples of commensalism
Some common examples of commensalism are:
- The remoras. Small saltwater fish capable of attaching themselves to larger and stronger animals, such as sharks, to take advantage of their fast swimming ability and move from one place to another quickly.
- Sea acorns. A genus of immobile marine crustaceans, they live on the shells of mussels, oysters and other bivalves, as tenants.
- Hermit crabs. With a soft abdomen, they take advantage of the empty shells of sea snails to enter and protect themselves, as if it were their own.
- Certain species of epiphytic plants, not parasites. They live on the branches of large trees, thus accessing levels of sunlightthat are scarcer at ground level .
commensalism in the desert
Some burrows are abandoned and inhabited by other species.
The desert habitat is one of the most extreme in the world and its flora and fauna are adapted to its difficult climatic conditions. This does not prevent them from forming commensal relationships, although they certainly occur less frequently than in other, more amiable environments . Examples of this are as follows:
- Burrows dug underground by rodents are often abandoned, and then other species can inhabit them and flee in the sun, as do certain types of snakes and scorpions.
- Desertowls and owls take refuge in holes made by other species within cacti, raising their young there and gaining protection from the sun and from other species.
- Birds of preyare frequent in the desert, like certain species of vultures, and they feed on any organic remains produced by the hunting of larger species.
Other types of interspecific relationships
In predation, one individual kills another for nutritional benefit.
In addition to commensalism and mutualism, which we have already talked about, there are the following types of interspecific relationships:
- Parasitism. It occurs when one species benefits from the other nutritionally or in another way, that is, it obtains benefits from it, but in this case causing damage of some kind. A perfect example of this are mosquitoes, which feed on the blood of animals to incubate their eggs, being able to in turn transmit diseases to which it serves as a contagion agent.
- symbiosis. It is a very narrow degree of mutualism, in which the species involved end up becoming codependent, that is, needing the presence of the other to survive or to complete their life cycles. A good example of this is the relationship between an alga and a fungus to form a lichen, exchanging structure for moisture and nutrients.
- competition. Quite the opposite of commensalism, it occurs when two species compete or face each other for access to the resources necessary to survive, so only one of them can benefit. This is the case, for example, of the competition between hyenas and vultures, or other African scavengers, for devouring the remains of the lion hunt .
- predation_ The fundamental type of interaction in the trophic chain consists in that one species (the predator) hunts and devours another (the prey ), thus obtaining a nutritional benefit and ending the existence of the other. This is what happens when a fox hunts down a rabbit and devours it.
- Amensalism. In this case, the interaction between the species is detrimental to one of them, without the other obtaining any type of benefit in return. This is the case with trees such as Eucalyptus or Walnut, for example, which prevent the growth of other plant species around them, without being directly benefited in the process .