Examples of Mutualism



What it looks like

Clownfish and sea anemones:  Clownfish are small, brightly-colored fish found in coral reefs.  They are frequently found in the tentacles of sea anemones, which typically capture their prey by paralyzing them with discharged cnidoblasts (nematocysts) , and then ingesting the animal within the gastrovascular cavity.  Studies have shown that a component of clownfish mucus inhibits the discharge of these cnidoblasts.

Clownfish and sea anemones present an example of facultative mutualism.  The clownfish benefits by having a protected home territory.  What does  the sea anemone gain from this arrangement?


Termites and intestinal flagellates:  Although termites can physically chew and ingest wood, they are incapable of chemically digesting cellulose into sugars.  They rely on intestinal flagellates, e.g. Pyrrsonympha spp. and Trichonympha spp. which are capable of producing cellulose.  These genera of flagellates reside in the hindgut of termites and provide nutrition for them.  They are not found anywhere else in nature. 

When a termite molts, it loses its hindgut and therefore loses its population of flagellates.  It reinfects itself by ingesting its (or some other termite’s) hindgut that has been eliminated.  (A pleasant thought, yes? 


A specimen of Pyrrsonympha is shown here.