Too much polyps extension on SPS

[dz6t]

Low oxygen, high nitrogen can also cause too much bad PE.

Veron talked about this in one of his books. The corals do not NEED to eat and seldom do in the shallow, clean reefs of the south pacific (he is talking about acropora). I think that he called it respiration, but that is not technically correct (I guess) and gas exchange is more like it. He also talked about how corals that could double their mass in several months would rarely risk extending their polyps if they did not have to - yes, it is a risk.

All of that said, it is usually a good sign... but be smart, understand what is happening and keep your eyes peeled for the other signs of unhappiness. Generally speaking, if a hairy acro has no PE all of a sudden, then you need to notice... same thing with one that never had much PE that all of a sudden has a lot.

My apologies if I mentioned this already, but I compare PE to full mantle extension in clams. This can oft be a sign of too little light, but people generally think that this is a good think since they are "out all of the way." Healthy clams do not often need to be fully extended to get enough energy from zoox under good lighting. Either PE or full mantle extension can be a good or bad sign.

+1.
Very well said.
It costs coral energy to extend its polyps. The rule of thumb for marine animal is that they dont spend energy if they don’t have to.

 

[bubbaque]

+1.
Very well said.
It costs coral energy to extend its polyps. The rule of thumb for marine animal is that they dont spend energy if they don’t have to.

what if holding the polyps in expends more energy and they only do so because fish will eat them during the day? Wouldn't they hold them in at night if they didn't need to extended them out? Just like our tanks, if a fish nips at them they hold them in. Once you get the fish out they will let the polyps out.

 

[29bonsaireef]

Low oxygen has a direct link to excessive PE. I have witnessed it enough times to believe this is true. Tanks with calm flow at the surface or little aeration with bring out more polyps. Good example would be how acros usually extend their polyps out during shipment, not because they are happy, because the oxygen has depleted and they are suffocating from the low levels.

In nature acropora rarely send out polyps during the day. They receive light energy through out the day, and won't risk fish nipping at their polyps. During the night they feed on planktonic creatures. No photosynthesis during the night, so the corals continue to collect energy/nutrients with their polyps. As well for gas exchange when there's not as much threat from fish.

 

[dz6t]

what if holding the polyps in expends more energy and they only do so because fish will eat them during the day? Wouldn't they hold them in at night if they didn't need to extended them out? Just like our tanks, if a fish nips at the moment they hold them in. Once you get the fish out they will let the polyps out.

In the ocean, plankton rise up from deep water at night and induce coral extend their polyps to feed. I am talking about hyper PE, not regular PE.

 

[MnFish1]

Does anyone have a study - that documents this? The reason I ask is not to question that sometimes it can be 'bad' - but how is it useful to know if it a problem or not. I.e. - what is 'normal extension'. what is 'hyperextension'? How long does hyperextension have to last to suggest that there is a 'problem'? Just trying to figure out how to use this information - when 'It can be good or it can be bad'. I guess the other question is - this is the first time ive seen someone ask about too much polyp extension - whereas many people who have dying coral or coral with problems after some 'event' talk about no polyp extension sometimes for weeks (if the coral survives).

To make a long post short - my guess is that it is far more likely for polyp extension to be a positive than a negative.

 

[Donsreef]

If my digi don't have PE then that's a sign something is going wrong in my tank.
PE is good.
Be concerned when you see Browning, bleaching & no PE.

 

[bubbaque]

I’d never be concerned by excessive polyp extension. Lack of it is when to worry, unless you have a fish that nips them.

 

[Donsreef]

Does anyone have a study - that documents this? The reason I ask is not to question that sometimes it can be 'bad' - but how is it useful to know if it a problem or not. I.e. - what is 'normal extension'. what is 'hyperextension'? How long does hyperextension have to last to suggest that there is a 'problem'? Just trying to figure out how to use this information - when 'It can be good or it can be bad'. I guess the other question is - this is the first time ive seen someone ask about too much polyp extension - whereas many people who have dying coral or coral with problems after some 'event' talk about no polyp extension sometimes for weeks (if the coral survives).

To make a long post short - my guess is that it is far more likely for polyp extension to be a positive than a negative.

1. PE is good
2. Be concerned when you don't have PE
3. Be concerned when you see Browning and bleaching and no PE

 

[29bonsaireef]

9/10 PE is a normal sign of a healthy coral. Our tanks are in many ways different from the ocean and natural reefs the corals are collected. It only makes sense that they would in some cases react/adapt differently to our tanks. In the case that there is something wrong the polyps usually appear more inflated, rather than just a fuzzy coral. IMO. for this to happen you really have to be running basically stagnant flow. Where there is very little oxygen/carbon dioxide being mixed into the water.

If you want to experiment.. just place a coral in a bucket of tank water for a few hours. The polyps will come out as the oxygen is depleted.

Also wanted to say I'm speaking on Acropora. Montis, Porites, and Seriatopora don't work exactly the same.

 

[bubbaque]

9/10 PE is a normal sign of a healthy coral. Our tanks are in many ways different from the ocean and natural reefs the corals are collected. It only makes sense that they would in some cases react/adapt differently to our tanks. In the case that there is something wrong the polyps usually appear more inflated, rather than just a fuzzy coral. IMO. for this to happen you really have to be running basically stagnant flow. Where there is very little oxygen/carbon dioxide being mixed into the water.

If you want to experiment.. just place a coral in a bucket of tank water for a few hours. The polyps will come out as the oxygen is depleted.

Also wanted to say I'm speaking on Acropora. Montis, Porites, and Seriatopora don't work exactly the same.

Do you think it's lack of oxygen or the water just being still? When I take coral pics I turn the pumps off for a minute or two and the polyps expand more in that short time.

 

[jda]

what if holding the polyps in expends more energy and they only do so because fish will eat them during the day? Wouldn't they hold them in at night if they didn't need to extended them out? Just like our tanks, if a fish nips at them they hold them in. Once you get the fish out they will let the polyps out.

They do not need to exchange gas as much during the day when the light is driving photosynthesis. It is more necessary at night since the zoox are not contributing any gas.

 

[29bonsaireef]

Do you think it's lack of oxygen or the water just being still? When I take coral pics I turn the pumps off for a minute or two and the polyps expand more in that short time.

To be honest, I don't have a positive answer to your question. I can say for sure there's a link between PE and gas levels in the water. I just don't know how fast the levels are affected when pumps and circulation stops. I will have to dig up some old pics from the 04 hurricanes. Power went out during the night and the next morning the acropora had insane PE, especially the smooth skins. Little to no color left in the polyps or corals, and everything RTN'd later that day.

Really would never look at PE as an issue. Unless your corals don't usually show much PE then suddenly you have a lot.

 

[jda]

Why is any of this so hard to believe? All of this is out there in books and some Dr. RHF articles. High temp can also lead to high PE - oxygen is less soluble in high temp. High aerobic load by sometimes dosing organic carbon can create levels of lower oxygen and PE can get larger. High levels of ammonia can lead to more PE as gas cannot really exchange as well. All of these are potentially bad signs, but they are also not all that common.

 

[bubbaque]

Why is any of this so hard to believe? All of this is out there in books and some Dr. RHF articles. High temp can also lead to high PE - oxygen is less soluble in high temp. High aerobic load by sometimes dosing organic carbon can create levels of lower oxygen and PE can get larger. High levels of ammonia can lead to more PE as gas cannot really exchange as well. All of these are potentially bad signs, but they are also not all that common.

It is hard to believe because I consider my corals to have great PE and I don't believe it's due to an issue, if anything it's the opposite.

 

[MnFish1]

To be honest, I don't have a positive answer to your question. I can say for sure there's a link between PE and gas levels in the water. I just don't know how fast the levels are affected when pumps and circulation stops. I will have to dig up some old pics from the 04 hurricanes. Power went out during the night and the next morning the acropora had insane PE, especially the smooth skins. Little to no color left in the polyps or corals, and everything RTN'd later that day.

That is coral dying. Not PE alone. The OP had PE with no other symptoms. That isn't proof that there is a link between PE and gas levels. That is proof that power failures kill coral (probably because of many factors -one if which is dissolved CO2/O2 in the water)

 

[MnFish1]

9/10 PE is a normal sign of a healthy coral. Our tanks are in many ways different from the ocean and natural reefs the corals are collected. It only makes sense that they would in some cases react/adapt differently to our tanks. In the case that there is something wrong the polyps usually appear more inflated, rather than just a fuzzy coral. IMO. for this to happen you really have to be running basically stagnant flow. Where there is very little oxygen/carbon dioxide being mixed into the water.

If you want to experiment.. just place a coral in a bucket of tank water for a few hours. The polyps will come out as the oxygen is depleted.

Also wanted to say I'm speaking on Acropora. Montis, Porites, and Seriatopora don't work exactly the same.

But if the light goes down they will also extend. And if you leave them in the bucket long enough the coral will die. Again - the question here is whether in a normal, flowing/working aquarium whether its likely that polyp extension is 'bad'. I agree with you thats its at least 9/10. probably 9.99/10 that PE is the sign of a healthy coral in a functioning aquarium

 

[dz6t]

Just do some google search for scientific papers and you can find some research about it.

Nano tank without skimmer, especially those AIO type, can have oxygen issue more often than not.

 

[Sabellafella]

This is a fake post - it must be lol. Like in a viagra website - my .... is too .... I dont understand. The funny thing is that people are actually trying to answer this question...

Lol actually I was in the same boat before - questioning myself about insane PE. Ive always chalked it up that nothing is bothering the acro.

 

[danreefman]

I feel, if they aren't furry something is wrong.

 

[Sabellafella]

I can tell you on the other hand from experience, if your montipora polyps stretch out far from the skeleton, it sorta tells you it needs more intense light. Not that its unhealthy or anything.

For acros, its all different for everyone. My tanks ph hits 8.4 during peak ours, skimmer line runs outside, use kalk. Doors are always open. The most surface agitation i could even do on my tank. Most likely not an oxygen issue. Nitrogen I can believe, but I've got my nitrates down about last year and all my acros PE are still insane. Ive had to have read everything. I have tons of people always ask me how I have such sick looking PE and I wish I can tell you guys but I just simply don't know why