A guide to the long term symbiotic interactions between species. We distinguish 6 different types of symbiosis interactions that have either a benefit, no effect or are harmful to the species involved in these interactions.
A symbiosis where one species obtains a benefit
Mutualism is the symbiosis between two species, where both obtain a benefit. Within mutualism, there are different categories depending on how much these species need each other for survival. An example of mutualism is the oxpeckers who clean parasites, such as ticks, from large mammals. Another example of mutualism is the microbiota in our own guts.
Commensalism is the interaction between two species. One benefits from the interaction and the other one experiences no benefit or harm. An example of commensalism is the remora living with the manatees. The Remoras feed on the manatee’s faeces. The manatee is not affected by this interaction, as he does not have to share resources, such as food, with the remora.
Parasitism is the interaction between two species, where one obtains benefit and the other one experiences harm. The parasite lives inside or on the organism where it can cause harm to its host. The parasite feeds either on the host itself or on some of the food the host consumes.
Amensalism is the symbiosis between two species. One benefits from the interaction and the other one experiences harm. Amensalism is a complex interaction and is often a unidirectional process. A clear case is where sheep or cattle trample the grass, the grass does not harm the hoofs of the animal but the grass suffers from being crushed. Of the Spanish ibex and certain weevils that feed on the same type of shrubs. Where the weevil has very little effect on the Ibex, the Ibex has detrimental effects on the weevils.
No species obtains a benefit
Neutralism is the symbiosis between two species, where both experience no benefit or harm. Examples of true neutralism are almost impossible to prove; this term describes situations where interactions between species are negligible or insignificant.
Competition is the interaction between two species where they both experience harm. This competition is often for resources, such as food, water, territory or for access to females for reproduction. This competition can be between members of the same species, called intraspecific, or between individuals of different species, called interspecific competition. Intraspecific competition is clearly visible in the red deer. They fight each other for the opportunity to mate with females for reproduction.