Species Interaction

Kendall Helms and Morgan Hoover

Background Information

Species interaction refers to the positive and negative interactions between species in a community. There are five major types of species interaction: Competition, Predation, Parasitism, Mutualism and Commensalism.


Competition is when more than one species are competing for the same limited resources. Both organisms in this relationship become harmed at some point. While one organism may be benefiting at the moment, the second organism is being harmed and leads to the decline of the population which ends up indirectly harming the first organism. There are two types of competition: Intraspecific and Interspecific. Intraspecific competition is competition between members of the same species. Interspecific competition is competition between members of different species. An example of competition would be cheetahs and lions. Cheetahs and lions both eat the same prey which makes it difficult for them to live together in the same community.


Predation is a species interaction in which one organism feeds on another. In this relationship, one organism is harmed while the other benefits. In this relationship there are two organisms, the predator and the prey. The predator is the organism that is hunting and also the organism that benefits. The prey is the animal being hunted on and the animal that is harmed. An example of predation would be an owl eating a mouse.


Parasitism is a non-mutual species interaction in which the first organism, the parasite, benefits from the expense of the other organism, the host. Parasitism is a type of predation but it is not the same because the parasite is usually much smaller than the predator. In this relationship, the host has no choice but to be fed off of whereas in predation, the prey has a slim chance to escape the predator. An example of parasitism would be the ocean sunfish with its 40 plus parasites such as sea lice and the shark tapeworm.


Mutualism is a symbiotic relationship in which both organisms benefit. In this relationship, the two organisms usually live together and work together to benefit from the interaction. An example of mutualism would be a shark and a remora. The remora fish attaches itself to the shark and uses it for protection while eating the scraps from the shark's meals while the shark gets cleaned by the remora fish.


Commensalism is a special species interaction in which one organism benefits from the other while the second organism is not harmed. An example of commensalism is an orchid growing on a tree. The orchids attach themselves to the high branches of the trees in order to get more sunlight while the tree is not benefiting or being harmed.

Science News Article

This article explains that humans are affecting the mutualistic relationships between animals and that we need to understand that we are messing with a fragile thing. Mutualistic relationships are fragile because if you disrupt it or corrupt it, you will lose both organisms that work better together rather than just one organism. Previously, scientists never payed much attention to mutualistic relationships and disregarded them as being important. Now scientists are starting to realize that we all need to pay more attention to mutualism and the relationships that come from it or else we will lose many organisms from the error in our ways.