What is Commensalism?
Commensalism is the biological interaction between two species in which one living being benefits and the other is neither benefited nor harmed.
This type of interaction between living things is studied through biology and ecology, in order to understand the various relationships that living things have and how they benefit from each other.
The word commensalism derives from the Latin cum mesa, which means “sharing the table.”
At first it was customary to use the word commensalism to refer to scavengers, which are those that feed on the remains of food left by other game animals.
For example, hyenas feed on food debris left by other animals such as lions.
In this case, the lions feed on the hunted animal and the remains they leave become the food of the hyenas and even other animals.
That is, they benefit from hunting and the food remains left by others, but the hunted animal does not obtain any benefit.
Types of commensalism
Commensalism is not only about the nutritional benefits that one species can obtain from another, it is also about the benefit of transportation, lodging or use of resources.
It is when one species takes advantage of another as a means of transportation. Generally, a smaller living being uses a much larger one as transport, which often does not even notice it.
The most common example is that of remoras that hook on sharks to move from one place to another.
It can also occur between plants and animals. In this case, some plants can disperse their seeds through the fur of other animals with which they have had contact.
A dog or cat does not benefit in this case, beyond the fun of walking in an open and natural space.
Metabiosis or Thanatocrecia
It refers to the use of a substance, waste or skeletons of another species, with which an animal can be benefited either to protect itself or to feed.
For example, hermit crabs protect their bodies in empty snail shells. There are also methanotrophic bacteria that feed on methane generated by methanogenic archaea.
Another example is the dung beetle, which benefits from the faeces of other animals.
Ws when a species (plant or animal) shelters or lodges in another, either inside or on it, in order to protect itself. The species that provides refuge generally does not obtain any type of benefit.
For example, birds build nests in the high branches of trees both to protect their eggs or young and to protect themselves.
Another case is that of the woodpecker that makes a hole in the trunk of the tree as a shelter.
So also do different species of monkeys that live on the branches of trees for the purpose of protection and because their food is right on the branches where they live.