symbiosis objective: to understand the relationships between species that allows them to survive
TRANSCRIPT
Symbiosis
Means ‘living together’; a partnership
Explains the close relationship between two species that allows them to ‘live together’ in order to survive
‘Inter-specific’: means that it occurs between different species
Why live together?
Due to competition for food and territory
Animals try to avoid direct competition and form a stable relationship (other than the predator-prey relationship)
Sharing of space and/or food supply
Animal kingdom
Nile crocodile & crocodile bird
Hermit crab & sea anemone
Buffalo & oxpecker
Shark & remora fish
Crocodile & bird
Nile crocodile Usually eats animals Allows bird to walk around its mouth
Crocodile bird Cleans parasites in croc’s teeth Removes and eats scraps of food Eats harmful leeches and parasites
Hermit crab & sea anemone
Hermit crab protects the crab
Sea anemone Gets leftover food
http://www.ms-starship.com/sciencenew/symbiosis.htm
Buffalo & oxpecker
Buffalo Lets the bird eat
Oxpecker Eats ticks and other
parasites off skin Warns buffalo of
danger
http://www.pbs.org/wnet/nature/enemiespartners.html/
3 categories of symbiotic interrelationships:
• Both species benefit from the association.Mutualism
• When one species benefits from the association and the other is unharmed.
Commensalism
• An interaction where one species lives in/on the host; the host is often harmed.
Parasitism
Mutualism
Both species benefit
Neither can survive without the other
Examples Tickbirds and rhinos Flowers and bees
Commensalism
“eating together at the same table”
Only one member benefits sharing space, defense, shelter, food
Neither will die if relationship is ended
E.g. Pearlfish & sea cucumber
http://www.ms-starship.com/sciencenew/symbiosis.htm
Parasitism
Not symbiotic
Causes harm to host
E.g. Fleas living off a dog