Interspecific relations

Interspecific relations

These are the relations between different species.

Mutualism

When both species benefit from the interaction. There are many examples. The bee and the flower. Bees fly from flower to flower gathering nectar, which they make into food, benefiting the bees. When they land in a flower, the bees get some pollen on their hairy bodies, and when they land in the next flower, some of the pollen from the first one rubs off, pollinating* the plant. This benefits the plants. In this mutualistic relationship, the bees get to eat, and the flowering plants get to reproduce.

Exploitation

When one species benefits from the interaction at the cost of the other species. Examples of this include:

predation – where one species huts and kills another species

parasitism - where a parasite lives in close association with and feeds off a host organism

Commensalism

When one species benefits from the interaction with no effect on the other species.

Most species of hermit crabs have long soft abdomens which are protected from predators by the adaptation of carrying around a salvaged empty seashell. As the hermit crab grows in size, it has to find a larger shell and abandon the previous one. It only uses empty shells, so the species that produced them are unaffected.

Antibiosis/Amensalism

When organisms interact and one species is unaffected but the other organisms have a negative effect. Penicillium is a group of common mould species, many of which produce antibiotics (such as penicillin). These antibiotics kill certain types of bacteria. The antibiotics produced by the moulds are simply a waste product, produced during their metabolism (as they break down their food). While the waste product kills bacteria, the penicillium are unaffected.

Competition

Where both organisms living in a similar niche are in competition for resources or space. This results in a negative outcome for each organism as it reduces the available resource for both parties.

The image (left) shows a lioness competing with some hyena for its kill.