Bleached and Bleaching polyps.

MUCHO REEF · 10:12 AM

Your polyps have been doing great for weeks, months, years even, then all of a sudden it happens. Or, maybe you're in your LFS, and you see something you like, but it's bleached or in a pre bleached state. What do you do? Do you throw them out? Do you consider making the purchased of the bleaching polyps at a reduced prices?

What is bleaching?

Bleaching - the mass exodus of large amounts of Zooxanthellae ( single cell algae within our corals which gives them their coloration/pigment ). Almost all of the factors within our reef tanks which result in bleaching are attributed to something we do/did, ....didn't do or should or shouldn't have done. This is but one of the reasons I'm so adamant about education. Knowing the names and prices of every polyp and not knowing the factors which could cause a complete expulsion of Zooxanthellae, to me, is like putting the cart before the horse. Attack me if I'm wrong, but I just replied to an email I got from a reefer who has spent $ 2,000 total on zoas, palys and a few other softies. His goal was to create this monster zoa tank. He purchased his/this first system in June of last year. He's running 250 watt DE - 10 K Halides on a magnetic ballast with 2 - T5 - 6 foot 10 K's as he wants optimal/quickest growth and 2 T5 actinics. He was going to remove the T5 10 K's after a year. He placed everything mid tank level to the top. Unfortunately, he received some very bad advice as most everything has begun to shift/change/bleach/morph, whatever we choose to call it.

Here's a direct quote from page 380, top left corner of Eric's Aquarium Corals book.

"Without the proper number of Zooxanthellae in their tissues, corals must rely almost entirely on dissolved nutrient uptake and heterotrophic feeding to meet their energy needs. Without their symbionts, the corals' ready carbon source produced by zooxanthellae photosynthesis is severely, if not totally, reduced. Furthermore, there is no guarantee that a bleached coral can or will adopt new zooxanthellae. Without the uptake of new symbionts, it will then LIKELY PERISH. At the least, metabolic activity becomes abnormal while the coral is in a bleached or partially bleached state, leading to changes in reproduction, reduced growth and possible tissue degeneration.

Translation - If the appropriate measures by each of us are not taken to adequately address that which leads to bleaching and those who make a concerted effort to cause/create a color shift/change, this is what will potentially happen. The coral will expel its Zooxanthellae from its tissue, the coral will have to rely on organic substrates to get its carbon for growth and development, the coral must now adapt to meet its needs for survival, you have impeded the inner natural functions for survival, there is no guarantee that the color will return and possible mortality ( death ) can occur. The very least that's going to happen is the breakdown of food and its transformation into energy will become abnormal and change and/or alter the reproductive rate, hinder growth and possible cause external damage to the coral.

So what are the contributing factors which causes bleaching?

Factors according to EB which will result in bleaching.

Below is a list of factors which can cause bleaching per EB.

Bacteria
chemicals
cilates
coccideans
darkness
fungi
heavy metals
higher temps
hypersalinty
hyposalinity
doldrum ( lack of water movement )
light
medications
noxious agents
physical stress
red spectral light
sedimentation
starvation
stress
temp changes
ultraviolet radiation

Hope this helps someone with a bleaching issue.

Mucho Reef

Part 2 coming, "Can you reverse the bleached, bleaching process?" Yes, yes you can, it will take time. I have done it and others have as well, providing the coral is still viable, by that I mean alive. Stay tuned for Part 2

jolson10450 · 01-27-2011, 07:28 AM

good read! looking forward to part 2!

Fordris · 01-27-2011, 10:01 AM

Good info man , thanks for the good read!

Wy Renegade · 01-27-2011, 12:07 PM

Excellent information; I've got some bleached Purple Hornets - I'll be following along, and maybe we'll conduct a little experiment as well. I'll post up a picture when I get a chance.

Sharkboy87 · 01-27-2011, 03:38 PM

Great article! I think alot of people don't realize the zooxanthellae actually leaves the coral, which is hard at times to reverse the process. When the sybiotic algae is gone, there is nothing left to make food for the coral, it cannot photosynthesize by itself.

Sir Patrick · 01-27-2011, 10:46 PM

I have always looked for a good explination for bleaching polyps.....and never found one!

Thx for sharing this info Mucho! I am really looking forward to hearing part 2. I have found bleached polyps, at stores or other reefers houses, and took them home, in hopes of them liking my tank and making a come back. Other than the ones that lost color from being burried in sand, or lost under rocks have ever came back for me. The unexplained color loss ones never made a come back, no matter what I did. Looking forward to a possible answer.

Mucho- would you mind if I added this info to our polyp info sticky? The thread is sort of a compilation of info, with info added as its found, and put together through contributions of knowledge from the forums-

General zoa/paly info- Need a quick answer, look here.

I have the perfect spot to add this info, if you dont mind.

Chris · 01-27-2011, 10:54 PM

I look forward to learning more on this as well Mucho

I have some polyps that sat in a sump w/o light for several months before being found and even after about 5 months now still haven't gained their color back (plain green but still would like to get it back). They are completely white, yet slowly spreading across the rock they have been on, which is a good sign cuz they have to be alive still atleast

MUCHO REEF · 07:16 AM

Thanks.

Excellent point Sharkboy. Most often, this mass expulsion is a desperete last ditch effort to survive a stressful condition. More often than not by the variables listed above. Great point you made though.

Chort55, yes, they will appear white, but that doesn't mean they are dead. The white you're seeing is most often the transparency through the coral after expulsion has occured. Usually from the gastric cavity and in some advanced cases, the entire dermal cell containing all of the algae can and will be expelled. Also, great point you made, the fact that they are spreading, proves that they are still alive and viable.

I would never purchase a bleached coral at full retail price though from a LFS. At a greatly reduced price, yes, and I have personally done so, as long as the coral is viable with tissue intact. Just hate seeing this when I do. It simply means the corals needs were not being met and the coral is simply trying to stay alive via mass expulsion of it's single cell algae.

Mucho Reef