This is an incomplete list of notable mutualistic symbiotic relationships, in which different species have a cooperative or mutually dependent relationship.

• Humans and cultivated plants
• Humans and domesticated animals
• Humans and intestinal bacteria
• Humans and the Greater Honeyguide bird (which may have a similar relationship with the Ratel or "honey badger")
• Small mammals and hypogeous fungi
• Algae and fungi in lichens
• Vascular plants and fungi in mycorrhizae
• Flowering plants and pollinators such as bees
• Leafcutter ants and the fungus they "farm" (note also the third mutualist: a bacterium that secretes a chemical that kills molds that would otherwise feed on the fungus "farmed" by the ants)
• Acacia Ants (Pseudomyrmex ferruginea) with the Swollen Thorn Acacia Tree (Acacia cornigera)
• Legumes and rhizobia (nitrogen-fixing bacteria)
• Euprymna squid (family Sepiolidae) and bioluminescent bacteria (Vibrio fischeri)
• Anglerfish and bioluminescent bacteria
• Moray eels and cleaner shrimp or cleaner fish at cleaning stations
• Goby fish and shrimp
• Groupers or snappers and gobies
• Corals and Zooxanthella
• Sea anemones and clownfish, crabs or shrimps
• Deep-sea pompeii worms and thermophilic bacteria
• Ruminants such as cows and their intestinal bacteria and protists
• Termites and their intestinal bacteria and protists
• Egyptian Plovers and crocodiles (not scientifically documented)
• Oxpeckers and rhinoceroses
• Polydnavirus and parasitoid wasps
• Cycads and cyanobacteria
• Foraminifera and algae
• Wolbachia bacteria and most insects
• Grasses and endophytic fungi
• Sponges and algae
• Aphids and Buchnera bacteria
• Azolla (water fern) and Anabaena (cyanobacteria)
• Ambrosia Beetles and fungi
• Sharks and remora

Fictional Symbiotic Relationships

• Venom and Carnage in Marvel Comics
• Midichlorians in Star Wars
• Yeerks in Animorphs
• Trill in Star Trek
• Goa'uld/Tok'ra in Stargate (see note below)
• The Indowy's "hair" in the Legacy of the Aldenata series.

Note: Stargate reference above is perhaps better stated as:

Tok'ra/Human - mutualism Goa'uld/Human - parasitism

Relationship is established by the moral code of the Goa'uld or Tok'ra co-existing with the human.

Note

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Some of these relationships are so close that we speak of the composite of two species as one unit, for example, we speak of the composite of algae and fungi as lichens. This is analogous to our speaking of a modulator and a demodulator as a modem. (See list of equipment pairs.)

biology Symbiosis