Parasitism

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Parasitism

• Parasite
• An organism that lives in or on another organism
  (host) and is dependent on that organism to
  complete its life cycle
• Results in the reduced fitness of the host
• May result in the hosts death
• Ectoparasites
• Endoparasites

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Parasite-host interaction

• Life cycles
• Definitive host
• Intermediate host
• Common in definitives host habitat
• Allows parasite to move to definitive host
• Prey of definitive host
• Change in behavior
• Near where definitive host feed
• High specialization (fewer hosts)

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Specialization

• Conditions to be successful
• Attach to host for long period
• Elaborate mouth parts
• Withstand hosts defensive responses
• May have to contend with enemies
• Most virulent strains not successful

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Coevolution host-parasite
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Parasitoids
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• Effects on Communities
• Different hosts have different susceptibility
• Meningeal brainworm in white-tailed deer and
  other cervids
• apparent competition
• Biological control
• Pro
• Highly specific
• Cons
• May start infecting new hosts
• Targeted host may evolve resistance