Big Word of the Month: Symbiosis

Many of the animals at the museum live with another animal of a different specie. They might live together because they seem to like each other or because they don’t bother one another and fit the exhibit well (large exhibits with 1 animal are pretty boring if that one animal doesn’t want to be in sight of guests). Some of the animals we have together are a donkey and dwarf goats, a steer and a boer goat, a pine snake and a greenish rat snake, a watersnake and a mud turtle, and a spotted turtle and a painted turtle. In the wild, different kinds of animals interact all the time. Those interactions are called symbiosis.


Symbiosis (pronounced: sym-BY-OH-sis or sym-BEE-OH-sis) can be defined as prolonged  interactions between different species of animals and/or plants which benefits or harms at least one of the individuals involved.

There are 4 different types of symbiosis: Mutualism, Commensalism, Parasitism and Amensalism.

++ Mutualism– An interaction is mutualistic when both species involved are benefiting from the relationship. As an example, my dog and I have a mutualistic relationship. He gets food, water, shelter, exercise and companionship from me and I get companionship, a jogging buddy, and a personal foot warmer in the winter, from him.

Rudy and Me
My dog, Rudy, and me.

+0 Commensalism– A relationship where one species benefits while the other is unaffected. An example could be Lightning, the donkey, and the Nigerian Dwarf Goats, Rocky and Patches. While, Lightning may get some amount of companionship from the two little goats, he generally seems unaffected when he is separated from them. It feels to me as though he has a fairly neutral attitude towards them. The little goats, however, are highly affected when apart from Lightning (screaming and bleating and acting very anxious). They likely have a herd leader and a protector in Lightning and are positively affected when he’s around.

Lightning and the Little Goats
Lightning guards his new toy

+- Parasitism– Parasites come in all forms! The easy ones are ticks, mosquitoes, fleas, chiggers, and any other blood/skin sucking bug. However, other plants and animals can be considered parasites as well (Cowbirds, Cukoos, Mistletoe). So long as one species in the relationship is negatively affected while the other is positively affected, a parasitic relationship is at hand. Because ticks are one of Marilyn’s favorite animals, I’ll add this picture just for her:


0- Amensalism– If commensalism is a neutral/positive (0+) relationship, its opposite is amensalism, a neutral/negative (0-) relationship. Of the 4 types of symbiosis, this is by far the rarest. Amensalism requires that one species be negatively impacted while another is not being impacted at all. The text book examples of this are Penicillin mold growing on stale bread and the Black Walnut tree. Ranger Greg was kind enough to look for some of these trees for me (a more pleasant option than waiting for some bread to mold), which he found just off the Dinosaur Trail. Black Walnut trees secrete a toxin into the soil as a natural part of their growth that inhibits or kills off plants that would otherwise grow near the tree. The smaller plants are negatively impacted, while the Black Walnut tree just keeps on growing.

Black Walnut Tree
Note the lack of undergrowth below the Black Walnut tree (left of center)

Many of the animals and plants on grounds have symbiotic relationships with other plants and animals nearby. Stop by the butterfly house and gardens to find some really cool relationships or find Ranger Greg and ask him about some of his favorites!


5 responses to Big Word of the Month: Symbiosis

  1. Marilyn says:

    Thanks so much for thinking of me with that disgusting picture, Sarah. I especially love that the tick is embedded in the skin. Yippy!

  2. Athena says:

    thanks so much for all the info! i’d love to use your website as a citation in my project but i cant find the publishers company, editors, or what city it was published in! can you help me?

  3. Alex says:

    do you possibly know of a mutualism pair that live in the taiga??? i cant find one anywhere… if you dont know of one off the top of your head then its fine but if you do can you plz tell me???

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