Better with company, or not?

In nature, most organisms are in constant interaction with others, and when two different species live in close contact for a long time, we call it Symbiosis. But as in every relationship, things are not always smooth. Sometimes the interaction is a friendly one (mutualism), with both parts benefiting from it, sometimes each part mind their own business (commensalism), living close to each other but without helping or harming much the other one, and sometimes… well… sometimes one side might try to get the best of the other one for its own benefit (parasitism)!

Here we have several puzzles showing different symbiotic interactions and the species involved in them. Help us solve them all!

Swedish summary:

I naturen befinner sig de flesta organismer i konstant interaktion med andra. När två olika arter lever tillsammans under en lång tid kallar vi det symbios. Precis som i alla förhållanden är det inte alltid så lätt. I en del fall gynnar interaktionen båda parterna, detta kallas mutualism. I andra fall gynnas bara en part medan den andra är helt opåverkad, något som kallas kommensalism. Ibland utnyttjar en organism en annan på ett sätt som påverkar den negativt, vilket kallas parasitism.

Här har vi flera pussel som visar olika symbiotiska förhållanden och de arter som är inblandade. Hjälp oss att lösa dem alla!


Since many species share the same ecological environment, it is useful for them to take advantage of what their neighbours can provide them. When two organisms establish this special interaction between them, it is called symbiosis. The symbiosis is established at the level of species (not individuals from the population), resulting in a long-term co-evolution that can be studied from different points of view. Most of our research is focused on the study of the evolutionary effects of symbiosis at the level of DNA, and how the genomes have adapted to this long-term partnership. By “reading” what is encoded in their genetic information, we can have a better understanding of many aspects related to their evolution, physiology and ecology.

The activity

What is better for learning than playing? We have created sets of puzzles showing three symbiotic interactions. In each puzzle, you will discover one example of mutualism, one commensalism and one parasitism. The puzzles follow specific themes: insects, plants, humans… choose your favourite!


Meet the illustrator

There are illustrations of the animals and plants in watercolor made by Lucie Yang at our station. Please come have a look at the cute paintings. There are bookmarks of some of the animals available. Take one of your favorite home.

Lucie Yang


Born in China, grew up in Los Angeles, and studied in both New York and Sweden, Lucie Yang is a self-taught watercolor/oil painting artist who recently left the actuarial field to start traveling worldwide. Inspirations for her illustrations can be traced back to keen daily life observations, playful interactions with animals/pets and fantasies ignited by emotions. She sees the world as a dreamy and colorful place so hope to bring others joy and values with brush and paper. In helping with Darwin Day activities, she drew up a series of watercolor symbiosis creatures in hoping to remind us of the precious uniqueness of nature, and the oneness that us human beings share with them.