There are three main types of symbiotic relationships: mutualism, commensalism, and parasitism. Mutualism benefits both organisms, like the relationship between bees and flowers where bees get nectar and flowers get pollination. Commensalism helps one organism without affecting the other, such as barnacles attaching to whales. Parasitism benefits one organism at the expense of the other, like ticks feeding on animal blood. Each relationship can be depicted as a plus for benefits, minus for harm, or zero for no effect.

1. Symbiotic Relationships
 symbiosis - the relationship between two
different individual species that live together
in a close relationship (living together)
 The word symbiosis can be broken down
into two parts to determine its meaning
 sym means together
 bio means life

2. Types of Symbiosis
 There are three
types of symbiotic
relationships
 Mutualism (+, +)
 Commensalism (+, 0)
 Parasitism (+, -)
 Each relationship
can be shown using
+ , - , or 0

3. Mutualism  mutualism - a
relationship where
both organisms
benefit
 A + / + relationship
 Think of a normal
friendship where
both friends gain
something from the
friendship
The acacia galls are homes to stinging
ants and the ants defend acacia from
other insects that would harm tree
leaves.

4. Mutualism
Flowers and their Pollinators
(Example: Bees and hummingbirds gather nectar and spread pollen.)

5. Mutualism
The moray eel
gets a clean
mouth and the
cleaner fish gets
a meal.

6. Mutualism
Birds and mammals eat berries and
fruits while the plant benefits by
the dispersal of it seeds.

7. The oxbird
gets rid of
the
parasites
on the
antelope
and allows
the oxbird
to have a
meal.
Mutualism

8. Mutualism
Cleaners eat insect pests from the
skin of animals.

9. Mutualism
Algae and Fungi (Lichen) - Alga
gets water and nutrients from
the fungus and the fungus gets
food from the algae.

10. Mutualism
Many herbivores such as cows, sheep,
deer, horses and rabbits depend on
bacteria that live in their stomachs to
break down the plant material.

11. Mutualism
The corals get food and the
algae are protected.

12. Commensalism
 commensalism – a
relationship where one
species benefits while the
other species remains
unaffected
 A + / 0 relationship
 Think of a friendship
where one of the friends
benefits while the other
doesn’t change
Barnacles adhering to the skin of a
whale

13. Commensalism
One species uses a second organism
for housing such as small mammals
or birds that lives in holes in trees or
orchids which live in trees.
Orchid in rainforest Venezuela

14. Cattle stir
up insects
as they eat
grass and
the
egrets
hang
around and
eat insects.
Commensalism

15. Commensalism
Clown fish
get their
protection
from the sea
anemone and
the anemone
is unaffected.

16. Commensalism
Shark eats
and the
remora
gets the
scraps left
by the
shark.

17. Parasitism
 parasitism – a relationship
where one organism
benefits (parasite) while the
species it depends on (host)
is harmed
 host – an organism on
which a parasite lives
 A + / - relationship
 Think of a friendship where
you might feel used by your
friend
Parasitic isopod on fish

18. Parasitism
Ticks and fleas that live in a host
animal's fur bite the animal and
drink its blood are parasites.

19. Parasitism
Mistletoe takes
moisture and
nutrients from
the plant while
the woody plant
has to support
itself and the
mistletoe.

20. Parasitism
Insects such as mosquitoes
feeding on a host are parasites.

21. The tick eats
the blood of
a human
and the
human
receives
Lyme
disease from
the tick.
Parasitism

22. Parasitism
Vines such as Kudzu growing on Trees

23. Parasitism
Tomato Hornworm with Wasp Eggs

24. Parasitism
The
tapeworm
attaches itself
to the
intestines of a
dog and the
tapeworm
takes
nutrients from
the dog.

25. Parasitism
Tapeworm or Hookworms living in
Host's Gut