Coral appreciation

[Full Hedge]

 

When we view corals we should not just be thinking of coral. What do i mean?

You should be viewing it as the coral holobiont. To me that includes, the coral itself, the zooxanthellae AND the whole host of bacteria living in the coral(mucus, tissue)

Why are corals interesting. Well, they live in really nutrient poor environments. Think of it like a desert. So how Do corals get the nutrition they need to even survive. Let alone thrive.

Corals are the ultimate nitrogen conserving organisms. Meaning what nitrogen they get, they keep. Corals host bacteria, in addition to the zooxanthellae. The bacteria helps the coral ‘eat’ their poop. 

So zoox and coral share a mutualistic relationship. We know that. But mutualistic relationships range from mutualism in one environment to parasitism in another. There are models based on cost benefit analysis for understanding and quantifying the relationship status (happily married to cheating)

To illustrate

Corals control the amount of nitrogen provided to the zoox and

Zooxanthellae has been shown to be capable of uptaking dissolved inorganic nitrogen. However, higher dissolved inorganic nitrogen has been shown to have a negative effect on coral calcification. 

Heterotrophic feeding of corals has been shown to increase growth rates. The opposite with adding Dissolved inorganic nitrogen(nitrate, ammonia) Pouring KNO3, probably a poor idea.

Look, you are the benevolent tyrant of the reef tank. You wanna favor the coral host not the zooxanthellae. Feed your coral host. If the coral controls both sex and finances, the zoox is less likely to cheat.

Basically when the environment change, the terms of trade change. Like inflation in an economy. Theres a winner (debtor), theres a loser(creditor).

Just one caveat. The nutrient enriched water(nitrogen rich) effect on coral growth only applicable in environments of high light (200micromol/M^2). Under less intense light, nitrogen may not be the limiting factor. 

I tried to write this as simpleeee as possible. Just to share the perspective

Feel free to ask me anything.