Polyp Extension = Happy Corals?

[NaH2O]

I've read over and over people saying, "I have good polyp extension, so my corals are happy" (I'm talking mainly SPS here). Does polyp extension really equate to "happy corals"? I thought polyps extend from chemical stimulus in the area, so why would this mean they are happy?

 

[Curtswearing]

What does polyp extension mean? Why is it a good thing? What if it means they are starving to death. What if if is nothing more than a stimulus/response issue?

Please explain!!!

 

[Elmo18]

This will be a good topic Nikki.

I know that one of my A. millepora have great polyp extension both at daylight hours and at night. One other coral has better polyp extension at night, than it does show at day light hours. Yet another one has better polyp extension during the daylight hours.

Corals usually feed at night, and I believe it may be a reason for lengthened polyp extension at night. However, does it mean that corals are not healthy when they don't show extension at night? How bout at daytime?

- Elmo

 

[DonW]

I have alot of frags. Some grow fast and some not at all. I'm only talking about the sps. The ones with great polyp extenstion grow fast. The ones with no polyp extension have not grown at all. In particular a 2" Acro that I've had for 4 months had 0 polyps that I could see. Last week It started showing polyps everywhere and has grow 1/4".

On the other hand they also may be a defense mechanism used to sting other coral that invade there space. I dont really think there is just one reason for great poly extension. But I do know mine showed very little until I got the ca up to 420.

My problem is how to tell when they are dead. I have a 5" staghorn colony that I thought was dead. Had no polyp extension from day one, turned green and grew algae all over it. I was going to remove it this weekend and this morning for the first time I saw a polyp extending from one of the tips.

Don

 

[NaH2O]

Maybe defining healthy corals would help....since being healthy probably equates to happiness? In my mind, a coral that shows good growth and color would be healthy. However, at increased temperatures a coral has good growth....but I don't believe all corals are healthy at these temperatures ----> bleaching/releasing of zoox.

Corals usually feed at night, and I believe it may be a reason for lengthened polyp extension at night.

I believe on the reef this is attributed to the higher nutrient concentration in the water? Perhaps our corals get accustomed to a nutrient level in the tank, and react accordingly to feeding times or if more nutrients are available during a certain time of day in the tank.

On the other hand they also may be a defense mechanism used to sting other coral that invade there space.

I wonder this as well. Colonies of different species nearby may cause a reaction with each other? Do SPS send out chemical defense (differing species play war)?

I do know mine showed very little until I got the ca up to 420.

Would the polyps respond if Calcium is too high/unbalanced?

 

[NaH2O]

Another point about polyp extension at night would be lack of predation. Corals are less likely to have their polyps attacked by fish at night, than they would during the daytime when fish are awake.

 

[DonW]

Moon light has a huge affect on my sps and softy polyp extesion. Ive been using a 23watt 4' t-5 actinic hellio 24/7 for the past two weeks as a experiment. For some reason color is getting better and corals are growing faster.

Don

 

[MikeS]

I notice that when I replace the lights on my tank with fresh ones, my corals retract for awhile....

Mike

 

[mojoreef]

Its really hard to relate Polyp extention to any one thing. Thier are so many uses and reasons a coral has it polyps extended or not you really couldnt tell if it were for good or bad reasons.

A coral can extend its polyps because it is not getting enough light, it can extend it because it is reacting to a chemical stimulis, or possible mechanical stimulas. These stimulis could be the result of sencing a nearby corals scent, or possibly food, or mechanically from something landed on it. It could extend its polyp as a indicator responce to reproduction, either chemically, or scent wise or even lighting conditions. Its really a long list of possiblities and/or combinations of possibilities.
Most corals will extend polyps and/or sweepers at night as preditation is lower and thats when its rivals are in biz. But again itss not carved in stone.


So if your looking at your coral and its polyps are out it might not be happy, it might be mad, or hurt, or starving, or looking to do the gigigigi.lol



Mike

 

[bobgoode]

Hi all, long-time reader, 1st time responder. As Mike has stated, polp-extension is an unknown with many possibly functions. It's use in respiration can also be thrown into the mix. Bob

 

[NaH2O]

Welcome to Reef Frontiers, Bob!

 

[bobgoode]

Thnx. Nikki. So does that mean SPS are Bipolar? Bob

 

[NaH2O]

LOL Bob...we could always add a supplement to the tank in order to correct the disorder. :lol:

 

[bobgoode]

Or, Nikki, we could all take it & then not worry if they're happy or not:lol: Bob

 

[Scooterman]

So, If your corals are growing, then most likely their happy, no matter what the polyps are doing right?

 

[bobgoode]

Yes, Scooterman, especially, if we're adding it & taking it too:exclaim: Bob

 

[bobgoode]

What I have noticed over the yrs. of keeping SPS is if a SPS had been polypoid & now has them retracted for a period of time, that SPS is the first to RTN with a stressor. With the exception of red bug infestation, I can not think of an instance where growth does not = health. Bob

 

[reedman]

I agree with Bob. Growth has a corellation to health.

I would not say that fast growth is related to better health or vice versa.

 

[bobgoode]

Reedman, I agree--actually forgot about overgrowth situitions whereby the zoox. are overextended energy-wise & shutdown eventually=unhealthy. Bob

 

[Maxx]

actually forgot about overgrowth situitions whereby the zoox. are overextended energy-wise & shutdown eventually=unhealthy.

When and how does this come about? What cirtcumstances can cause an overgrowth?
Nick