Polyp Extention

[youngtimothy]

I recently traded a large chunk of blue tenuis to a LFS and I went bact to the store and the piece I traded had awesome polyp extention, much more then my tank. what are some Ideas to what cause polyp extention. I know my water is just as good if not better then theirs. I did notice their flow was les then mine and they had halides, I have overdriven T-5's, my bulbs are newer. the polyps where more brown/rust colored and in my tank they are greyer.

 

[Anthony Calfo]

Polyp extension is not a reliable sign of good health (or bad health). Store tanks often show better extension because of older or weaker lighting (the corals are panning for light when they overextend) or heavy bioloads (lots of extra carbon/sugars)

Some folks even cheat in their so-called coral vitamin products and the like by simply adding sugar. That will make your corals polyp out bigtime (though adding sugars is a bad long term habit). So when you hear people say "I LOVE the smell of X brand coral supplement...it smells like pear or apple juice!" Well..there is a reason wht it smells that way

 

[Troylee]

Very interesting Anthony.... I know a friend of mine his tank has very low to zero flow and his polyp extension is down right amazing... Every time I got a frag from him I could never get it to look like his... I was blaming it on flow lol...

 

[Anthony Calfo]

Flow is only a mild influence in some cases (LPS receiving too much flow will stay retracted for safety, lest vessicles get torn from their bodies...LOL).

No...polyp extension is more about food/waste dynamics. Catching food, catching light (to an extent, as with the aforementioned panning for light all corals do in lower light environs), purging waste, etc

And keep in mind that one's hardware above the tank is not the end of the story. Just because the lights are big and bad doesn't mean they are good. A slight discoloration to the water from lack of carbon, ozone and or water changes can absolutely CRIPPLE light penetration at depth. So a bright looking fixture could still fail to support corals if the water its illuminating isn't maintained.

Also, a small amount of dust or debris, salt crust, etcetera on the bulbs or lenses is likewise crippling to light penetration.

For whatever reason, if the light doesnt reach the corals, they will stretch and pan for it in an attempt to spread out zoox and catch more of the weakly available light.

Same goes for feeding. If corals don't get enough food/nitrogen, they will starve and also stretch polyps with the hope of increasing their chances of catching prey or trapping more debris in the high surface area of mucous covered tissue.

Another reason is to purge waste. But also purge debris. A particularly scummy mfg sells a "coral supplement" that is basically fine sand packaged in the South Pacific and sold in overpriced little jars. It is insoluble calcium carbonate!!! But it claims to benefit corals and improve polyp extension. Only one of those two things is true...and that's still not good. This coral sand/powder is sediment(!) that sticks to coral tissues and they have to expand to slough it off! That is biologically expensive to an animal already not getting peak bacterioplankton, zooplankton, etc

When I see big polyp expansion, I'm usually looking to see whats wrong. Its usually not a healthy sign. Prime example in the every day is the sps enthusiasts that keep zero nitrates, a low fish load, no DSB and no other significant means of delivering nutrition to their corals. As such, those frags pan for light for some months (even over a year if enough fish waste lets them hang in long enough) before they ?mysteriously" die and the sps keeper is puzzled. I'm just puzzled that they are puzzled. LOL

Basic biology here, thankfully so.

 

[Troylee]

Great info Anthony glad to have you abroad here... I noticed most of my sps had never had huge polyp extension and was leaning towards the the flow thing myself like I mentioned above... After jumping on the np bio pellets band wagon I have noticed a big increase in polyp extension and it made me believe exactly what your describing... As my nutrients went down the polyps extended there for I thought most likely they were starting to starve and kicked the amino acid in.... So far so well but I have had like 4 pieces that have been with me for years have some tissue loss so I never up-Ed the dosage to the recommended dosage... I truly believe in lighting also.. I have noticed zoos and paly under rocks or near the bottom stretch incredibly long to capture the light... once again great info and thanks for sharing!!!!! Btw love your c2c bro every tank I build has one lol...1smile1

 

[youngtimothy]

Thanks! I feel better now, I know threir lights are probable well overdue for change, which makes since to me, LFS stores are different then home aquarists they only need to keep things tell they sell. changing bilbs don't make money, super clean water doesnt make money, selling corals makes money and that's what they are there for. I get it! I just thought great polyp extention was a good thing, never thought about what they were actualy doing.

 

[spscrazy]

wow here I've been trying & trying to figure out why my corals were growing but wouldn't extend polyps like I've seen on others corals. kept thinking I was doing something wrong.

 

[swannyson7]

What type of fish you house in your system? I used to have a flame angel in my 180, and all of my SPS had very little polyp extension (he was an SPS nibbler). As soon as I got rid of him, I noticed an increase in PE almost overnight. Maybe it was just a coincidence, but I hadn't changed anything else with my tank, so it seems all too convenient.

 

[Anthony Calfo]

respectfully, the fishes don' make a difference. Corals on the reef sustain various and sustained nipping all day, any or every day. They respond to an immediate stimulus and then quickly get back to business.

Whats more common is that when a fish dies or is caught and removed in aquaria, the keeper unconsciously makes another change that affects nutrient levels and/or water clarity (stirring sediments, disturbing substrates, doing a water change, draining the tank partly to catch the fish and agitating rock/sand, etc)

 

[Tab28]

This topic has been on my mind for awhile. And thanks for answered a number of my thoughts on it. I have several SPS for years in my older 60 gallon. The polyps were always open day/night. I have upgraded to a 120 over a year ago and I almost never see my polyps open. My water quality is good both Phos and Trates at 0. They are growing and still have the bright colors but I do miss seeing the Milli/Acro swaying in the water flow.

 

[Paul_N]

respectfully, the fishes don' make a difference. Corals on the reef sustain various and sustained nipping all day, any or every day. They respond to an immediate stimulus and then quickly get back to business.

I experienced this with a Larabicus quadrilineatus (Red Sea Cleaner Wrasse) that was sold to me by a lfs that will remain nameless...lol It was eating the polyps on my millepora non stop but as soon as it would swim away the polyps would start to extend. Took me two days to get that darn fish out of my tank.

 

[butts182]

Wow, lots of great info there from Anthony. Generally i would think alk, flow, fish, and lighting would be the main players in daytime pe.

 

[Tabasco1]

Just trying to keep up here... great information, thanks! One question... what is a c2c? Need to know if I need one!

 

[swannyson7]

"C2C" is a coast to coast overflow (designed by Anthony Calfo) for a means of draining water from the DT down to your sump. If you google it, you'll be able to find tons of info on this great setup.

 

[returnofsid]

Different SPS corals will experience different polyp extension, in different systems, as you've noticed. Some SPS will ONLY extend their polyps at night, which is actually natural. Some SPS will extend their polyps all the time. I do think that flow, nutrients, lighting, or lack of any of these, does play a part in polyp extension, but I don't completely understand the relationship. I do agree that PE isn't necessarily a sign of a "happy coral." A lot of people use PE to judge the "happiness" of their coral, which is a mistake. Sure it makes for great photos and is very eye appealing, but not an accurate sign of coral health. I'll be following along, reading Anthony's threads, to learn from one of the MASTERS!

 

[Anthony Calfo]

actually...you bring up an excellent additional point, my friend!

In the context of feeding (prey capture), we can look at polyp extension cycles as usually indicative of what they feed on. Corals that only extend polyps at night tend to specifically seek zooplankton. Corals that extend all day long or variously are more often mixed-plankter (type) feeders (bacterio, phyto and/pr zooplankton as well).

Speaking in generalities here. But its a good clue when you are trying to reckon a corals needs. Big polyps = big food, small polyps = small food. Its really as simple as it seems sometimes.

 

[returnofsid]

That would explain why my Hydnophora EATS other corals? lol

 

[MattL22]

So is good pe defintly a sign that something is wrong in tank??

 

[AcroholicReefer]

Polyp extension can mean two things from my experience. It can indicate that the coral is extremely healthy or extremely unhealthy, which is why it is so hard to understand polyp extension.

In a healthy acro, polyp extension means that the coral is eating and producing waste on a regular basis. This shows that the polyps have an adequate supply of zooxanthellae to consume on a regular basis.

It can also mean that the coral is starving. This usually happens in ULNS and results in thin branches and pale colors (sometimes a bit bright). After you compare the polyp extension on a healthy acro vs one in an ULNS, it is easy to tell the difference. It can also happen with wild acros that are "fresh". This basically is a clear sign that the polyp is not going to make it and the next day is will start to loose its tissue. A good way to check this out is squirt the acro with a turkey baster and tank water. If the polyps retract, they acro is healthy enough, at the moment atleast.