Commensalism is a relationship between two organisms where
one organism benefits but the other is not harmed and does not benefit at the
same time.
Mutualism is a relationship between two organisms where both
of them benefit.
Parasitism is a relationship between two organisms where one
benefits and the other is harmed. The organism that is harmed is called a host
where the benefitting organism lives in or on.
Crocodile bird and crocodile
The Egyptian plover is also known as the crocodile bird. The
relationship between the two is called mutualism. The crocodile bird benefits
by eating the food that is stuck in between the teeth of the crocodile. This
benefits the crocodile because food that gets stuck in its teeth can actually
cause infection.
Remora and shark
Remora and shark have a relationship called commensalism.
The remora is a fish that swims under the shark or attaches itself to the shark.
It benefits from the shark because it uses the shark as a means of
transportation and at the same time, it gets to eat the left overs of the
shark. The shark also serves as a bodyguard for these remoras. The shark is not
harmed in this process but it does not benefit either.
Flea and dog
A flea and a dog have a relationship called parasitism. The
dog is somewhat harmed by the flea, as it sucks its blood to feed itself and
injects saliva into the skin of the dog which causes discomfort to the dog. The
dog is the host on which the flea lives on.
Barnacle and whale
Barnacles and whales have a relationship that is called
commensalism. The barnacle benefits from the whale by sticking to a whale. As
the whale travels through plankton-rich waters, the barnacles get to feed on
them through filter feeding. They also benefit because the whale acts as a mode
of transportation and protection as they go to one feeding site to another.
Tapeworm and human
The tapeworm and human relationship is an example of
parasitism. The tapeworm is a parasite that feeds off the human host. They
enter the human host and reside in the intestines. They benefit from their host
by eating the partly digested food that goes through the digestive tract. The
host is harmed because it deprives the host from getting the nutrients it needs
from the digested food.
Algae and fungus
Algae and fungus share a mutualistic relationship. The
fungus benefits by growing around the algae which provides it a constant supply
of food through photosynthesis of the algae. The algae benefits from the water and
nutrients the fungus absorbs.
Clown fish and sea anemone
The clown fish and sea anemone both benefit from their relationship,
which makes this mutualism. The clownfish makes the sea anemone its home
because anemone have stinging tentacles which provide the clownfish protection.
At the same time, the clownfish protects the sea anemone from other fishes that
eat anemone.
Termite and digestive tract microorganisms
Termites and the microorganisms that live in their digestive
tract share a mutualistic relationship. The termites rely on these
microorganisms to help them breakdown the sugars they ingest from wood into something
that they can digest. The microorganisms live off what the termites ingest.
Dwarf mistletoe and pine tree
The dwarf mistletoe and pine tree have a relationship called
parasitism. The dwarf mistletoe extends fibers into the bark of the tree and
taps into it, absorbing the nutrients and water from the tree. This causes harm
to the tree because the lack of nutrients and water makes it more vulnerable to
diseases, drought and the like.
Spanish moss and oak tree
The Spanish moss benefits from the oak tree but the oak tree
does not benefit from it nor is it harmed. The Spanish moss grow on the
branches of the oak tree keeping itself out of the reach of herbivores. They
are capable of making their own food so they do not feed on the oak tree’s
nutrients. This makes their relationship commensalism.