Mutualism happens when organisms of two different species are related in a way that the association is beneficial for both.
This relationship is called interspecific because it happens between different species, and harmonica for being positive for both organisms.
Types of Mutualism
optional mutualism
Optional mutualism happens when organisms are able to live independently but gain some benefits when they associate.
Mutualism can also be called protocooperation, however, this nomenclature is falling into disuse.
An example of facultative mutualism is between birds and mammals such as horses, rhinos and buffaloes. Birds feed on ticks on the skin of these animals, freeing them from the nuisance they provide.
mandatory mutualism
Obligatory mutualism, also called symbiosis, happens when the survival of one or both organisms depends on the relationship between them, that is, at least one of them would not survive in isolation.
An example of obligatory mutualism is the relationship of termites with protozoa. Protozoa live in the termite intestine and digest the cellulose that the termite is unable to digest.
Another example of obligatory mutualism are lichens, associations of fungi with algae or fungi with cyanobacteria.
In this ecological relationship, algae and cyanobacteria provide the fungus with organic compounds obtained by means of photosynthesis and fungi prevent dehydration and provide mineral salts for algae and cyanobacteria.
Lichens.
Mutualisms can also be classified according to the type of relationship established between the organisms:
defensive mutualism
In defensive mutualism, one of the organisms usually receives food and in return offers the other protection from predators and parasites.
An example of defensive mutualism is ants and acacia plants. Acacias provide food and their thorns provide protection for ants.
Ants, in turn, protect the acacia by attacking herbivores and ridding the plant of fungi.
Trophic Mutualism
In trophic mutualism, each of the organisms provides the other with nutrients that it cannot produce naturally. Usually this type of relationship happens with mutualistic fungi and bacteria.
An example of mutualism with fungi is mycorrhiza, which occurs in association with plant roots. In these cases, the fungus obtains glucose and sucrose from the plant and in exchange provides water and mineral salts.
The relationship between bacteria Rhizobium and legumes is another example of trophic mutualism. In this case, the bacteria make nitrogen available to the legumes and these provide the bacteria with the nutrients it obtains in photosynthesis.
Bacteria Rhizobium and legumes
dispersive mutualism
In dispersive mutualism, insects, birds and mammals feed on plants and, in turn, disperse seeds and pollen that are deposited in their bodies.
An example of dispersive mutualism is bees, which feed on the nectar of flowers and carry pollen to other plants, which will allow the fertilization of eggs in other places.
Other examples of mutualism
Paguro crab and sea anemone
The hermit crab uses shells abandoned by snails to protect itself from predators. Sea anemones tend to attach themselves to the surface of these shells.
In this mutualistic relationship, the sea anemone benefits from locomotion, as it is not able to move by itself. And the crab gains protection, as the anemone has stinging cells that release a toxin when predators come into contact.
This mutualism is optional, as both the sea anemone and the crab can live alone, but both benefit from the relationship.
Clown fish and sea anemone
Sea anemones also establish a mutualistic relationship with clownfish. These fish use anemones as a refuge and breeding site away from predators.
In exchange, the fish protect the anemone from predators, provide nutrients from its fecal matter and clean the anemones, preventing the permanence of parasites.
Anemones feed on fish, however, clownfish have a mucosa that protects them from the lethal action of anemones, enabling mutualism between these species.
Also get to know the ecological relationship commensalism.
