Wildlife
Symbiosis is a relationship between two organisms that's beneficial to one (commensal) or both (true symbiote). For instance, giant clams have algae living within them. They each recycle the other's waste products and supply their partner with nutrients. Symbiosis can exist between different kinds of organism, such as between plants and fungi or plants and animals, as well as between different species.
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Colourless corals
Rising sea temperatures force corals to expel their pigmented algae, causing coral bleaching.
Rising sea temperatures force corals to expel their pigmented algae, causing coral bleaching.
A living cave
Unfortunately for the sea cucumber, pearl fish go to extreme measures to stay safe.
Unfortunately for the sea cucumber, pearl fish go to extreme measures to stay safe.
Curious cover
Anemones, urchins and even sea snakes provide protective cover for juvenile fish.
Anemones, urchins and even sea snakes provide protective cover for juvenile fish.
Fish cleaning station
Large groupers employ smaller fish called wrasse to clean them.
Large groupers employ smaller fish called wrasse to clean them.
Faithful follower
Seychelles magpie robins follow the tortoises' trail.
Seychelles magpie robins follow the tortoises' trail.
Symbiosis (from Ancient Greek σύν "together" and βίωσις "living") is close and often long-term interaction between different biological species. In 1877, Bennett used the word symbiosis (which previously had been used of people living together in community) to describe the mutualistic relationship in lichens. In 1879, by the German mycologist Heinrich Anton de Bary, defined it as "the living together of unlike organisms."
The definition of symbiosis is controversial among scientists. Some believe symbiosis should only refer to persistent mutualisms, while others believe it should apply to any types of persistent biological interactions (i.e. mutualistic, commensalistic, or parasitic).
Some symbiotic relationships are obligate, meaning that both symbionts entirely depend on each other for survival. For example, many lichens consist of fungal and photosynthetic symbionts that cannot live on their own. Others are facultative, meaning that they can, but do not have to live with the other organism.
Symbiotic relationships include those associations in which one organism lives on another (ectosymbiosis, such as mistletoe), or where one partner lives inside the other (endosymbiosis, such as lactobacilli and other bacteria in humans or zooxanthelles in corals).
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Other Behavioural pattern behaviours
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Bee orchids 
Pied flycatcher
Hairy wood ant
Scottish wood ant
Wood ants
Yellow meadow ant
Adonis blue
Giant tube worm
Pompeii worm