SymbiosisSpecies InteractionTopic *1014

Ms. Morris

Symbiosis

• A close ecological relationship between the individuals of two (or more) different species

• Sometimes it benefits both species• Sometimes one species benefits at

the other's expense • Sometimes neither species benefits

Mutualism

• BOTH species benefits– One species gets food, while another

gets shelter– One species gets protection, while

another gets food

Mutualism – Ants and Acacia treesImage: www.discoverlife.org

Commensalism

• ONE species benefits, the other is unaffected– One species gets food, while the other is

not harmed or benefited– One species gets protection, while the

other is not harmed or benefited

                                

                             

Commensalism – Pseudoscorpions on a fly’s leg

Image: pick5.pick.uga.edu

Parasitism

• One species benefits, the other is harmed but not killed– One species gets food, while the other is

weakened

• If the host species was killed, what would happen to the parasite species?

Parasitism - Tomato hornworm is covered with cocoons of pupating braconid wasps

Image: www.cals.ncsu.edu

Neutralism

• Neither species is benefited or harmed– Both species live in the same

community, but do not interact

Neutralism – Both cacti and tarantulas live in the desert

Images: www.tetch.com

Amensalism

• One species is harmed, while the other is not affected– Forest fires – all species die, but no

species benefits– Floral industry – we cut flowers, the

flowers die, but we don’t get a real benefit (other than it looks pretty)

Image: www.affordable-flowers.com Image: www.tidysflowers.com

Amensalism – Flowers will die, but we get no benefit from it

Competition

• Both species are harmed– Species fight for food– Organisms within a species fight for a

mate– comp.mov

Competition – Evergreen Trees are competing for light and nutrients

                              

      

Interspecies – Between two different species

Intraspecies - Within a certain species

Which is this picture?

Image: www.for.gov.bc.ca

Questions

• What is the difference between parasitism and amensalism?

• Why don’t parasites let their hosts die?• What kind of relationship do ants and

acacia trees have?• Why doesn’t a competitive relationship

benefit any species?• Hand this in to Ms. Morris by the

end of the day!!! (10 points)