Often when we think of ecosystems and interactions between organisms, we immediately think of food webs dynamics because it’s one of the major players in what drives ecosystem health. Predator-prey dynamics are more dramatic. Watching the lioness catch the zebra is exciting. But thriving ecosystems contain more than the standard coyote-eats-rabbit-eats-grass. Adaptations are often acquired. And those who can’t adapt, make a friend.

Even in the non-human living world, organisms form relationships if for no other reason than convenience. Mutualism is one of those relationships in which two species involved benefit from the relationship. So in this time of transition, when we must embrace the need to adapt, here are 10 examples of mutualistic relationships where critters just learned to get along.

1. Bees and flowering plants

Probably the most obvious (and therefore, overlooked) mutualistic relationship is that of pollinators and flowers. When a bee lands on a flower to drink that sweet, delicious nectar, pollen from the flower’s stamen rubs off on the bee’s body. As the bee moves to the next flower, that pollen is transferred from the bee’s body to the flower’s stigma inciting pollination.

2. Oxpeckers and black rhinos

The name “oxpecker” should easily give away the nature of this relationship. Oxpeckers ride on the backs of large mammals like the black rhinoceros and eat the parasites that have taken residence on the mammal’s skin. As a result, the mammals are parasite free and also provide a warning to the oxpeckers by making noise if a predator approaches.

Full disclosure: There is some debate about whether or not oxpeckers are considered a mutualistic relationship because they may not remove enough parasites for it to be beneficial to the mammal.


Image credit: Iheart Rhinos

3. Clownfish and sea anemone

The classic example of mutualism is probably the first that comes to mind for many people. As a means of self-defense, sea anemones have tentacles that shoot a neurotoxin-filled harpoon to paralyze incoming fish/prey. Clownfish species are immune to the anemone’s sting and are provided protection from predators as a result. In return, clownfish provide an extra layer of protection to sea anemones by chasing away predators and the anemone get to be passive feeders and eat the floating leftovers of the clownfish’s meals.


Image credit: Marco Flerli

4. Bacteria and human stomachs

As humans we also have the opportunity to be a part of a mutualistic relationship with the bacteria that live in our stomach. Millions of species of bacteria receive optimal conditions in which to live while helping us break down food that our bodies would otherwise have difficulty digesting and to make life-necessary nutrients available.

5. Manta ray and cleaner fish

They may look solemn and lonesome, but manta rays have quite the following. Many marine organisms use the ray’s large body as protection and shelter, creating a very one-sided relationship. However, cleaner fish, such as various species of cichlids and gobies, are worthwhile friends to manta rays because they “clean” the ray by eating parasites on the ray’s skin.

6. Ants and aphids

Aphids, also known as greenflies, use piercing mouth parts to suck fluids from plants. Their waste product consists of sucrose and nutrients that are beneficial to ants. Aphids take appreciation of the ants’ love of their “honeydew” by riding the backs of ants as they travel. The aphids get transportation to new plants, and the ants get to eat the honeydew.


Image credit: Paul Bertner, Rainforest Photography

7. Orchids and mycorrhizal fungi

Orchids are an interesting family of plants as a result of their ornate flower structure, but many of them also utilize a fungus to help the seeds germinate. Orchid seeds contain very little nutrient reserves. When the seed is infected by a mycorrhizal fungus, the fungus has access to the embryo inside the seed and can pass nutrients to the embryo. As the plant goes through photosynthesis, the fungus extracts carbohydrates from the plant’s roots.

8. The Common Spider Crab and algae

The Common Spider Crab lives in the substrate—the sediment and mud—at the bottom of bays and estuaries. As a form of camouflage, the crab places bits of algae and decomposing matter on its shell. The crab gets to hide from predators (and prey) and the algae get a place to live.

9. Pistol Shrimp and Goby Fish

Pistol shrimp are excellent at construction and create burrows for protection because they also have poor eyesight. Gobies have excellent eyesight and like to hide in nooks, but are not very skilled when it comes to building burrows. Fortunately, both of these organisms get along, which allows the goby to act as a watchman while the pistol shrimp digs a burrow for them to share.


Image credit: Small Science

10. Lichens

The body of a lichen is comprised of algae surrounded by the filaments of a fungus. The algae and fungus both need carbohydrates to live. As producers, algae are able to undergo photosynthesis to create those carbs, and in lichens, the fungus harvests the carbs and helps them diffuse throughout the cell walls of the alga. Being attached to a fungus allows the alga to travel to new habitats.


Image credit: Sam Velder

Curious about a science topic and want to make a suggestion? Email me at chenillehw@outlook.com.