Symbiosis is the relationship between two or more distinct biological organisms. Many of these interactions work together to the benefit of both beings, as sometimes one cannot survive without the other. Others become bonds in which one organism suffers as the other feeds off it, such as parasites. Algae, classified as plants, are living organisms that interact with a number of living things in nature. Algae can be multi-cellular or unicellular. Because algae come in more than 30,000 species, including green, red, and brown, it is not unusual that it would have symbiotic relationships with other living organisms throughout nature.
When we look at algae's symbiotic relationships, one of first that comes to mind is its indistinguishable relationship to sea life of all kinds. Algae, known as zooxanthellae, are important to marine life, including corals, jellyfish, and other living organisms. These algae provide essential nutrients to life under the sea. If corals don't feed on zooxanthellae, they cannot build beautiful reefs. Because algae are at the bottom of the food chain, they are a primary food source and first step in feeding other living things on the planet.
Another symbiotic relationship of algae is lichens. Lichen is a unique term used to represent the bond between a bunch of fungus that connects with green algae or cyanobacterium as its symbiont. The fungi and algae species in lichen can live on their own; however, lichen as a whole needs these algae in order to survive. Because algae are plants, lichens use them to reflect the sun, igniting the process of photosynthesis in order to get food. Lichens also use these symbionts to fix atmospheric nitrogen for later use.
Algae also have symbiotic relationships with foraminifera. Foraminifera are a large group of amoebas with reticulating pseudopods, or fake feet, and thin strands of cytoplasm that form an extensive network. These tiny organisms use their pseudopods to move and grab food. A number of foraminifera have green, red, golden or other algae as their endosymbionts, organisms living within another living thing. Some of these algae are used to initiate the process of photosynthesis.
Algae do not only provide for others; they, too, have beneficial relationships with other living organisms. Green algae live in close proximity to some freshwater sponges. These sponges protect the delicate algae from predators. In turn, the sponges receive oxygen and sugars which help them grow.
Because algae are important to marine life, some are looking to them as a way to open people's eyes to environmental issues. Many people are beginning to see algae's symbiotic relationships affect more than just a few living things. Their relationship extends indirectly to a multitude of living things, including humans.