Mutualistic Coevolution

Mutualistic coevolution is something that I am going to focus on over the next couple of weeks. It is where species coevolve into a mutualistic symbiotic relationship.

I am choosing to discuss the mutualistic relationship between clownfish and anemones because although it is common knowledge that clownfish can live unharmed in an anemone, it is not common knowledge what the reason for this is.

Does the protection come from the mucous of the anemone itself? Or, does the clownfish alter its own mucous coating to allow it to occupy the anemone unharmed?

Brooks and Mariscal (1984) tested these questions by exposing a clownfish to a constructed surrogate anemone for a period of time before exposing to a real anemone, observing how long it takes for the clownfish to acclimate. They concluded, due to the rapid acclimation rate, that it was the clownfish altering its own mucous during acclimation to form protection from the anemone.

Different subspecies of clownfish along with different subspecies of anemones can show preference to each other, and each subspecies of clownfish can share its own mutualistic bond with its particular subspecies of anemone. For example, ocellaris clownfish will only occupy the magnifica anemone. The reason for this is unknown, possibly due to convenience of not having to alter its mucous to a new anemone.

 

References:

Photo: http://www.colormaniacs.com/blog/?m=201003 - date cited 26/03/2014

Brooks, W. R. & Mariscal, R. N. 1984. The acclimation of anemone fishes to sea anemones: Protection by changes in the fish’s mucous coat. Journal of Experimental Marine Biology and Ecology, 80(3), 277-285.