Parasitism
Parasitism is a non-mutual symbiotic relationship between species, where one species, the
parasite, benefits at the expense of the other, the host. Traditionally
parasite referred primarily to organisms visible to the naked eye, or macroparasites.
Parasite now includes microparasites, which are typically smaller, such as viruses and bacteria. Some examples of parasites include the plants mistletoe and cuscuta, and animals such as hookworms. Unlike predators, parasites do not kill their host, are generally much smaller than their host, and will often live in or on their host for an extended period. Both are special cases of consumer-resource interactions. Parasites show a high degree of specialization, and reproduce at a faster rate than their hosts. Classic examples of parasitism include interactions between vertebrate hosts and tapeworms, flukes, the
Plasmodium species, and fleas. Parasitism differs from the parasitoid relationship because parasitoids generally kill their hosts.