BIOL-208 Lecture Notes - Lecture 15: Deer, Amphipoda, Amphiprioninae
17 Dec 2016
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Mutualism, Parasitism, and Disease
- Interactions
- Symbiotic: mutually beneficial relationship requiring close proximity
- Non symbiotic: mutually beneficial relationship not requiring close proximity
- Such as a bird eating berries and depositing the seeds in poop elsewhere
- Don't specifically need each other; their lives are not dependent on each
other
- Mutualisms: interactions between individuals of different species that benefit both
- Facultative mutualism: species does not require mutualistic partner for
survival
- Fruiting plants and birds
- Wrasse eating parasites from gills of larger fish
- Some ants and aphids
- Some clownfish and anemone
- Obligate mutualism: species are dependent on mutualistic relationship
- Coral and zooxanthellae
- Some algae and fungi (lichens)
- Orchids and fungi
- Large herbivores and bacteria
- This one is not known for sure, not known if the bacteria
can live on its own because it only occurs in the digestive
system of the herbivore
- Study of mutualisms generally far behind that of predator - prey
interactions because some mutualisms are hard to find examples of
- Complex interactions
- categories of positive, negative, and neutral interactions among organisms
- positive-positive:Mutualism
- Positive-negative: Exploitation
- Positive-neutral: commensalism
- Negative-negative: competition
- Neutral-neutral: neutralism
- Neutral-negative:amensalism
Species A
Species B
positive
neutral
negative
positive
mutualism
commensalism
exploitation
neutral
neutralism
amensalism
negative
competition
- Mutualism to exploitation is a continuum
- Parasitic and mutualistic interactions in nature are very diverse
- Defy easy generalization: positive or negative?
- Easier to consider some representative examples that show diversity
find more resources at oneclass.com
find more resources at oneclass.com
- Parasites
- Control: behaviour modification by parasites
- Many parasites alter behaviour of host in ways that benefit
transmission and reproduction of parasite
- Acanthocephalans
- Amphipods
- Starlings
- Parasite in poop, prey eat poop, gets infected and goes against
usual behaviour, gets eaten by predator, infects and gets pooped
out, cycle continues
- Infestation: ghost moose and water ticks
- Winter ticks feed on variety of hosts (cervids)
- Unique among ticks: single host species for all stages
- Moose gets so infested by ticks, rubs off it outer coat and appears
white
- Interactions: parasitism and competition
- Adelina tribolii protozoan parasite of Tribolium (flour beetles)
- Lowers density of T. castaneum but has little effect on T.
confusum
- Presence of parasite reverses outcome of competition between
species
- Reciprocal benefits
- Ants and Bullshorn Acacia
- Acacia tree provides a number of benefits to the ants such as
shelter in its hollow thorns, protein from the bulb at the tips of
leaflets, and nectar that is secreted near base of leaves
- Ant provides several forms of protection to the acacia by lowering
herbivorous insects, removing vines, killing other nearby plants,
clearing leaf litter, and protecting from fire
- Plants benefit from ants: increase growth and survival of shoots
- Zooxanthellae and corals
- Zooxanthellae get nutrients such as nitrogen and phosphorous
from coral
- Coral gets organic compounds from zooxanthellae through
photosynthesis
- Ecology of Disease
- Disease: a typical condition in organisms causing physiological impairment
- Caused by a variety of factors
- Ecological approach to understand
- Pathogen population size
- Processes within host (how immune the individual is)
- Processes outside host (how it is contracted)
- Transmission efficiency important
- Transmission types
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Symbiotic: mutually beneficial relationship requiring close proximity. Non symbiotic: mutually beneficial relationship not requiring close proximity. Such as a bird eating berries and depositing the seeds in poop elsewhere. Don"t specifically need each other; their lives are not dependent on each other. Mutualisms: interactions between individuals of different species that benefit both. Facultative mutualism: species does not require mutualistic partner for survival. Wrasse eating parasites from gills of larger fish. Obligate mutualism: species are dependent on mutualistic relationship. This one is not known for sure, not known if the bacteria can live on its own because it only occurs in the digestive system of the herbivore. Study of mutualisms generally far behind that of predator - prey interactions because some mutualisms are hard to find examples of. Complex interactions categories of positive, negative, and neutral interactions among organisms. Species b (cid:3451) positive neutral negative positive mutualism commensalism exploitation neutral negative neutralism amensalism competition.
