Transcript Parasitism

Species
Interaction
Types of Species Interactions
• Predation
• Competition
• Symbiosis
– Mutualism
– Commensalism
– Parasitism
Predation
• Predation is any interaction between
two organisms in which one organism
(the predator) consumes all or part of
another organism (the prey).
Herbivore-Plant Interactions
• A herbivore
grazing on a
plant is
another
example of
predation.
• Usually, only
part of the prey
is eaten by the
predator.
Prey Defenses
• Predation usually results in
the evolution of defensive
adaptations in prey.
• These can include:
– Chemical defenses
(toxins, poison, acrid
sprays)
– Behavior (living in
groups, scouts, alarm
calls)
– Morphological features
(spines, color, structures
that allow you to run fast
or detect predators), and
other traits
Caterpillar with Venomous Spines
Camouflage
• Camouflage is
protective
coloration in
which an animal
resembles its
background.
Camouflage
• In addition to
matching the
background, the
animal often
uses body
position to
enhance the
illusion.
Competition
• Competition in an interaction between
two organisms that are using the same
limited resource.
• Competition can be within the same
species (intraspecific) or between
different species (interspecific).
• Two species share a requirement for a
limited resource  reduces fitness of
one or both species
Symbiosis
• Symbiosis is an intimate relationship
between different species in which at
least one species depends upon the
relationship to survive.
Types of Symbiosis
• Mutualism: Both partners benefit from
the relationship (+, +)
• Commensalism: One partner benefits
from the relationship; the other partner
is not affected (+, 0)
• Parasitism: One partner benefits from
the relationship; the other partner is
harmed (+, -)
Mutualism – both species benefit from the interaction
two species provide resources or services
to each other  enhances fitness of both species
Examples of Mutualism
Flowers and their Pollinators:
bees and hummingbirds gather nectar
and spread pollen
Cleaners eat insect pests from the skin
of animals. (ex: Egyptian plover cleans
giraffes and buffaloes)
Many herbivores such as cows, sheep,
deer, horses and rabbits depend on
bacteria that live in their stomachs to
break down the plant material.
Commensalism
Commensalism  one species receives a
resource from another species 
enhances fitness of one species; no
affect on the fitness of the other species
one benefits and the other is neither
harmed nor helped.
The clownfish lives among the forest
of tentacles of an anemone and is
protected from potential predators.
Some birds live among cattle to eat the
insects stirred up as they walk.
Example: egrets who hunt for insects
near a grazing animal's mouth.
One animal attaching itself to another
for transportation such as barnacles
attach to shells or whales or a shrimp
riding on a sea slugs.
barnacles on whale’s
tail and clam
shrimp riding on a
sea slug
Parasitism
One organism, usually physically smaller of
the two (the parasite) benefits and the
other (the host) is harmed
One species feeds on another  enhances
fitness of parsite but reduced fitness of
host
Ticks and fleas that live in a host
animal's fur bite the animal and
drink its blood are parasites.
Insects such as mosquitoes
feeding on a host are parasites.
Vines such as Kudzu growing on trees
Tomato Hornworm with Wasp Eggs