RTN's association with a polyp

[invincible569]

There has been different theories as to what RTN really is. Some say its an actual disease while some say its just a response factor to the environment its in. We have all seen some of our SPS RTN, and since the zooxanthellae's are jumping off the coral, wouldnt the polyp jump off first? The polyp is what really gives the coral its continued growth and other misc things... and looking at an RTN stem, you see no polyp and no tissue. Does the polyp jump out into the water first creating the start of a case of RTN? As seen in the
"polyp bailout" here:

http://www.zeovit.com/forums/showthread.php?t=3029

[o2manyfish]

Invinv,

I think RTN, is just a simple way to say something died. If you take into account that something along the lines of 99% of the living coral is water, as soon as life ceases or is challenged the tissue immediately dissolves, rots, disintegrates, etc.

Whether tissue, polyps, zooxan - all our primarily water based, and our more than eager to go back to being water.

IMO, RTN is just a fancy way of saying - I dun Killed Dat Purty Coral.

Dave B

[Diesel3443]

Invinv,

IMO, RTN is just a fancy way of saying - I dun Killed Dat Purty Coral.

Dave B

I totally agree

Its a blanket term IMO, necrosis happens for a variety of reasons. Hobbists then name it RTN for fast and STN for slow.

[SeanCallan]

I don't know if I agree with the

IMO, RTN is just a fancy way of saying - I dun Killed Dat Purty Coral.

I've seen some RTN's come back to life. I think it's really a stress factor. RTN always seems to take place when there's a sudden change in the system. Look at how SPS TN when they get 'shocked' after shipping or if suddenly your salt drops or your temp increases.

I think it's more of a stress response, just like humans who are overly stressed you have side effects. In both instances, excessive stress can lead to death. But I don't think TN is a death warrant..imo...which isn't worth much

[o2manyfish]

Sean,

I think you have to watch the wording carefully -- The portion of the coral that actually RTN's is toasted. Once the tissue comes off a particular area of the coral - The coral does not / and cannot come back to life. The portion of the coral that does not RTN may grow back over the dead area -

But once an area of a coral has RTN'd a polyp will never grow back into the same polyp opening.

RTN does not necessarily mean 100% loss of a colony or a frag. However, I feel very confident stating that the portion of the coral that suffers Tissue loss, whether rapid (RTN) or slow (STN) regardless of the reasons, will never come back to life --- But may create a surface area for life to grow upon.


As for comparing to humans with a stress response, using your example, if someone got stressed, and as a result peeled the skin off of their arm entirely... Well you can see where recovery probably won't happen.

You have to remember the physiology of the corals - Skeleton, covered in a very thin layer of tissue (skin). Once that skin is gone, so has the life.

(Not meant to sound belittling (sp), sarcastic, or condescending).

Dave B

[invincible569]

I do too agree that its just a fancy name and I also mean the part that dies off. But I am most likely interested in the process of what steps a coral takes when it starts to RTN. Im sure a lot of you have experienced this and when a coral looks very unhealthy, you dont see the polyps out. Is this a sign that the polyp has left the skeleton and therefore the zooxanthellae is next because it cannot function through its chemical symbiosis with the polyp? I know sometime, the polyp is only retracted, but then there are times when its about to die off. Hope that makes better sense.

[Diesel3443]

Makes better sense now Maybe Gary will chime in here

[invincible569]

I will most likely experiment this out soon. I will frag a coral and place it in a container and monitor it to see if I see anything fly off besides the tissue.

[o2manyfish]

Invinc,

Why don't you come out to LA for a couple of days - I have plenty of pcs you can experiment on.

We can shoot up the coast to one of the bio labs, and use a 1600x digital microscope you can see what fly's off then

Dave B


PS - You gotta post a full tank shot (in focus) before making flight arrangements.

[invincible569]

I will be in L.A. some time in my life. Not sure when though! There's a lot of sight seeing like the Salinas Valley State Prison.

The full tank shot will be out shortly.

[Diesel3443]

Dave, you know edward has a couple teasers floating around. I bet Skipper's seen it

[o2manyfish]

Blah Blah Blah Blah Blah Blah Blah Blah




Dave B

[Detritivore]

edward, according to veron (COTW book 1) zoox can also live in the tissue between polyps (gastro-something-something)

[invincible569]

jonah, thats right. Maybe I should separate them out by stem tissue and by polyp.

I took home a pink hyacinthius that did not show any polyp extension from a LFS 2 days ago. The next day, it was bright white. By looking at the pic, it looks as if the polyps "bailed out" before the entire coral tissue went into self destruct. Here's a pic if you look close:

[Aged Salt]

Hi Edward, gosh, that occurred quickly Probably in this case a big change in photoadaptation in your clear, low-nutrient waters allowed a marked increase in light transmission to the coral. Do you know how long the coral resided at your lfs? Bob