SYMBIOSISThe term symbiosis (from the Greek:, sym,

"with"; and, biosis, "living") commonly describes close and often long-term interactions

between different biological species. The term was first used in 1879 by the German

mycologist, Heinrich Anton de Bary, who defined it as: "the living together of unlike

organisms".

Mutualism

An example of mutual symbiosis is the relationship between Ocellaris clownfish that dwell among the tentacles of Ritteri sea anemones. The territorial fish protects the anemone from anemone-eating fish, and in turn the stinging tentacles of the anemone protect the clownfish from its predators (a special mucus on the clownfish protects it from the stinging tentacles).

Mutualism is a biological interaction between individuals of two different species, where both individuals derive a fitness benefit, for example increased survivorship. Similar interactions within a species are known as co-operation.

Red-billed Oxpecker, Buphagus erythrorhynchus of east AfricaYellow-billed Oxpecker, Buphagus africanus of most of sub-saharan Africa.

Nile Crocodile (Crocodylus niloticus) with Egyptian Plover or Crocodile Bird (Pluvianus aegyptius)

Lichens

Organism A Organism B

Benefit? Benefit?

Mycorrhiza

Organism A Organism B

Benefit? Benefit?

Commensalism…is a term employed in ecology to describe a relationship between two living

organisms where one benefits and the other is not significantly harmed or helped (like a bird living in a tree).

The word derives from the Latin com mensa, meaning sharing a table.

Remoras (shark suckers) on a nurse shark

Barnacles on a whale

Parasitism• Parasitism is a type of symbiotic

relationship between organisms of different species in which one, the parasite, benefits from a prolonged, close association with the other, the host, which is harmed.

• The harm and benefit in parasitic interactions concern the biological fitness of the organisms involved. Parasites reduce host fitness in many ways. Parasites increase their fitness by exploiting hosts for food, habitat and dispersal.