List of symbiotic relationships
This is an incomplete list of notable mutualistic symbiotic relationships, in which different species have a cooperative or mutually dependent relationship. This relationship can be endosymbiotic, whereby an organism resides in another's body or cells.
There are three types of symbiosis: mutualism, commensalism, and parasitism. Mutualism is symbiosis in which both organisms benefit. Commensalism is symbiosis in which one organism benefits and the other is not harmed or helped. Parasitism is symbiosis in which one organism benefits and the other is harmed to their death.
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.
|Symbiosis by luci||Endosymbiont||Role of endosymbiont||Role of host|
|Euprymna scolopes (Mollusca)||Vibrio fischeri||Counter-illumination via bioluminescence||Reproduction|
|Legumes||Rhizobia||Fixed nitrogen||Photosynthesis (principally as the dicarboxylic acids malate and succinate)|
|Actinorhizal plants||Frankia bacteria||Fixed nitrogen||Photosynthesis (principally as the dicarboxylic acids malate and succinate)|
|Anglerfish||Bioluminescent bacteria||Bioluminescent lure for prey capture||Protection|
|Vascular plants||mycorrhizae||Sequestering of phosphate ions from soil, disease protection||Photosynthates|
|Parasitoid wasps||Polydnavirus||Immune suppression of parasite host||Propagation of the virus|
|Poaceae||Endophytic fungi||Disease prevention, Drought tolerance||Photosynthates|
|Host||Endosymbiont||Role of endosymbiont||Role of host|
|Coral (Cnidaria), other invertebrates||Zoochlorellae (green algae), zooxanthellae (“non-green” algae, typically dinoflagellates, cryptomonads, chrysomonads or diatoms)||Photosynthates||Protection, inorganic nutrients|
|Foraminifera, ciliates (protists)||Variety of algae||Photosynthates||Locomotion, protection, inorganic nutrients|
|Sponges (Porifera)||Variety of algae (Often green-algae)||Photosynthates||Protection, inorganic nutrients|
|Hydra viridis (Cnidaria)||Chlorella||Photosynthates||Inorganic nutrients|
|Elysia viridis (Mollusca)||Codium fragile||Photosynthates||Locomotion, protection, inorganic nutrients|
|Convoluta roscoffensis (Platyhelminthes, traditionally)||Tetraselmis convolutae||Locomotion, protection, inorganic nutrients|
|Pompeii worm, Alvinella pompejana (Annelida)||Thermophilic chemoautotrophic bacteria||Insulation, chemosynthates||Locomotion, inorganic nutrients|
|Mole salamanders||Oophila||Oxygen (from photosynthesis)||Carbon dioxide (from respiration)|
|Riftia pachyptila (Annelida)||Bacteria|
|Solemya velum (Mollusca)||Sulfur-oxidizing chemoautotrophic bacteria|
|Orphium frutescens||Xylocopa violacea (Female Carpenter Bee)||nutrients for larvae||Locomotion of Reproduction|
- Humans and intestinal bacteria
- Ruminants such as cows and their intestinal bacteria and protists
- Termites and their intestinal bacteria and protists
- Aphids and Buchnera bacteria
Other symbiotic relationships
- Humans and cultivated plants
- Humans and domesticated animals
- Humans and the Greater Honeyguide bird (which may have a similar relationship with the Ratel or "honey badger")
- Flowering plants and pollinators such as bees and flies
- 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)
- Leafhopper and meat ant
- Acacia Ants (Pseudomyrmex ferruginea) with the Swollen Thorn Acacia Tree (Acacia cornigera)
- Moray eels and cleaner shrimp or cleaner fish at cleaning stations
- Goby fish and shrimp
- Sea anemones and clownfish, crabs or shrimps (the bright colours of clownfish attract predators; the anemone provides shelter for the clownfish)
- Egyptian Plovers and Nile crocodiles (not scientifically documented, likely purely mythical.)
- Oxpeckers and white rhinoceroses
- Oxpeckers and Black rhinoceroses
- Oxpeckers and orange rhinoceroses
- Cycads and cyanobacteria
- Azolla (water fern) and Anabaena (cyanobacteria)
- Ambrosia Beetles and fungi
- bees and flowers
- Sharks and remora- commensalism
- Fig trees and Amazon fruit bats
- Common fig and Blastophaga psenes
- Lichen a mutualism between a fungus and algae (usually green-algae or cyanobacteria)
- Squirrel and a tree (commensalism)
- Mangrove Finches and Mangroves in the Galapagos
- Coyote and American Badger
- Simarouba amara: The small yellow flowers are thought to be pollinated by insects, the resulting fruits are dispersed by animals including monkeys, birds and fruit bats and the seeds are dispersed by leaf cutter ants.
- Olive baboon and African elephant
- Dictyostelium discoideum and farmed bacteria 
- Young, R.E. & C.F. Roper 1976. Bioluminescent countershading in midwater animals: evidence from living squid. Science 191(4231): 1046–1048.1251214
- Matthias Habetha et al. The Hydra viridis / Chlorella symbiosis.
- R.K. Trench, J.E. Boyle and D.C. Smith (1973). "The Association between Chloroplasts of Codium fragile and the Mollusc Elysia viridis. I. Characteristics of isolated Codium chloroplasts". Proceedings of the Royal Society of London. Series B, Biological Sciences 184 (1074): 51–61. doi:10.1098/rspb.1973.0030.
- Douglas, A E (1998). "Nutritional interactions in insect-microbial symbioses: Aphids and their symbiotic bacteria Buchnera". Annual Review of Entomology 43: 17–38. doi:10.1146/annurev.ento.43.1.17. PMID 15012383. ISSN 00664170.
- Brock DA, Douglas TE, Queller DC, Strassmann JE (20 January 2011 2011). "Primitive agriculture in a social amoeba". Nature 469 (7330): 393–396. doi:10.1038/nature09668. PMID 21248849.