Thursday, April 7, 2011

Blog # 9 Define the different forms of community interaction: competition, commensalism, mutualism, predation, parasitism Give an example and a picture for each

Competition is a contest between individuals, groups, animals, etc. for territory, a niche, or a location of resources. It arises whenever two or more parties strive for a goal which cannot be shared. Competition occurs naturally between living organisms which co-exist in the same environment. For example, animals compete over water supplies, food, and mates, etc. Humans compete for water, food, and mates, though when these needs are met deep rivalries often arise over the pursuit of wealth, prestige, and fame. Business is often associated with competition as most companies are in competition with at least one other firm over the same group of customers. Commensalism describes a relationship between two living organisms where one benefits and the other is not significantly harmed or helped. Mutualism is any relationship between individuals of different species where both individuals derive a benefit. An example of mutual symbiosis is the relationship between the ocellaris clownfish that dwell among the tentacles of Ritteri sea anemones. The territorial fish protects the anemone from anemone-eating fish, and in turn the stinging tentacles of the anemone protect the clownfish from its predators. A special mucus on the clownfish protects it from the stinging tentacles. Predation describes a biological interaction where a predator (an organism that is hunting) feeds on its prey (the organism that is attacked). Predators may or may not kill their prey prior to feeding on them, but the act of predation always results in the death of its prey and the eventual absorption of the prey's tissue through consumption. A parasitic relationship is one in which one member of the association benefits while the other is harmed. Parasitic symbioses take many forms, from endoparasites that live within the host's body to ectoparasites that live on its surface. In addition, parasites may be necrotrophic, which is to say they kill their host, or biotrophic, meaning they rely on their host's surviving. Biotrophic parasitism is an extremely successful mode of life. Depending on the definition used, as many as half of all animals have at least one parasitic phase in their life cycles, and it is also frequent in plants and fungi. Moreover, almost all free-living animals are host to one or more parasite taxa. An example of a biotrophic relationship would be a tick feeding on the blood of its host.













 

1 comment:

  1. It is ok for you to use a photograph I made (lion) but you should mention the photographers name and a link to the original.
    Thank you,
    Benny

    ReplyDelete