branch ECOLOGY

Leading to PREDATION
=INTERSPECIFIC INTERACTIONS= [image:] Interactions between members of '''different''' species ==Types of Interspecific Interactions== [image:] '''Mutualism''' When both species benefit from the interaction. In this example the bird is cleaning the crocodiles teeth, which helps the crocodile, and the bird is getting a meal. [image:] '''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 [image:] '''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. [image:] '''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. [image:] '''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. ==Summary== [image:]
Credit: Ben Himme