S

SymbiosisObjective: To understand the relationships between species that allows them to survive.

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/

Shark & remora fish

Shark Lets the fish eat

Remora Fish Eats parasites Gets the shark’s leftovers

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