Coral and Colonies

Go and find a piece of plate coral close to the surface and spend a minute looking closely between the coral fingers and amongst the polyps.

Upon the surface and within the mucous layer, in the flesh and in the matrix of the coral skeleton, reside a fantastic collection of highly adapted, mutually independent symbiotic partners. These symbionts include representatives of all the major groupings of the tree of life. There are bacterial, archean, protozoan, fungal, algal and animal communities occurring throughout all levels of the coral colony.

These genetically diverse populations themselves are intricately integrated with each other and the animal hosts into stable structures which we call coral colonies.

A wide assortment of animals inhabits the complex microhabitat of the coral plate. These residents are often sculpted and coloured in ways that provide almost complete camouflage against the background of their particular host coral.

The residents have complicated relationships with their host corals:

They clean debris from their home which ensures vital sunlight is not blocked and helps prevent infections.

They actively repel coral carnivores like the Crown of Thorns Starfish, nipping and stinging the thousands of starfish feet that fill the spaces between the fingers as the animal settles down to eat.

They eat away at infection fronts, slowing the disease and removing infective material before it can slough away and spread the disease more widely as exemplified in the service provided by the Hairy Black Fingered Crab in the slowing of White Syndrome.

Each without the other would fail to thrive. In each other’s company the whole becomes more than the sum of its parts and long term survival becomes a possibility. You without your immune system would also fail to thrive. You wouldn’t be whole because something fundamental to your survival as an organism was not in place. Likewise, in the absence of these diverse coral based micro-communities, coral reefs as we know them would not be possible.

This feature of interdependence is not limited to coral.

Your own body is as dramatic an example of this most fundamental characteristic of life on Earth as is anything on the reef.

There are ten times more non-human cells in your body than there are human ones and at the genetic level, your 25 thousand genes are seriously outnumbered by the 3 million non-human genes that are in operation in the colony that you refer to in the first person.