could someone define coral aggressiveness

[Anonymous]

Coral aggressiveness is a pretty broad phrase that means lots of different things. Basically it comes down to corals trying to protect their space from encroachment by other corals that might interfere with light, food supply, currents, whatever.

There are lots of different mechanisms. The ones you can see involve corals trying to sting each other, or overgrow and shadow each other. Especially at night, some corals have the ability to put out really long "sweeper" tentacles that would surprise you by their length. The defense you can't see typically involves putting poisons (chemicals) into the water to discourage the growth of neighboring corals.

The aggressive and defensive attacks are pretty specific as to what is being attacked, most of the time. Chances are, a feather duster might not be perceived as a threat because generally plate corals occur in deeper water than feather dusters. Not sure about the mushrooms.

-Jim

 

[Anonymous]

I am in agreement with all of what jim said, I would just like to add a few tid bits.

The rating of medium high agressiveness is a little ambiguous in my opinion. Some corals will be very agressive to some and not others. The stinging cell on a coral is called nematocysts (sp?). The sweeper tenticals jim mentioned have high concentrations of these cells. They are used to keep neighboring corals repressed so that the agressor can claim more area to grow. Anchor and bubble corals are know for their sweepers. Mushrooms can posses a suprising amount of nematocysts, and will develope more on their edges when they feel threatened. I don't believe that the duster will be bothered at all, and depending on the mushroom, it may be just as agressive as the plate.
I will warn that plates are not amoung the easier corals to care for, in any case, the best of luck to you.

 

[Anonymous]

As we think about replacing the plate coral, I was hoping that someone could clarify a question about aggressiveness. Does a med-hi aggressive coral damage anything within a broad radius around it? or does this only mean that it can do damage to something that it might physically touch with its tentacles? We had feather dusters within about 6" of the plate when it was inflated and mushrooms about 8" away. Were we just lucky that they weren't bothered?