It took me some time to come up with a topic for this presentation. I am a little too addicted to information, and I have a bad habit of trying to compress too much information into my thoughts and words. I have started to become acutely aware of this fact, and of the necessity of narrowing the focus of topics to make them more digestable. When I started thinking about this lecture, I was planning on covering coral biology. I wanted to pull some unique material from papers I have read and amassed, in order to compare and contrast what happens (or what we think happens) in our aquaria compared to the wild communities. I really don't know what I was thinking, because it occurred to me that there are nine hundred page books and thousands of articles on this subject. Here I was, thinking that by some act of faith, I could do cover it in a few pages! Fortunately, I came to my senses...for if I hadn't, you would all be here listening to me till the millenium, I fear. Get that coffee brewing! LOL

I was just reading the latest issue of Aquarium Frontiers Online, and read several articles on corals and the (not so) recent work of Laurie Richardson in the keys on Star coral disease, also represented as White Plague Type II. I was a bit disappointed by the coverage, as there were several points in the articles that were not quite accurate, and I became worried that many people who read this journal would, once again, give all these"mysterious and terrible" bacteria a bad name. As some of you may know, I have been working with bacterial studies in corals for the past year or so, and trying to ascertain their respective roles in aquaria...both in health and disease. I think this is an area that is largely misunderstood, and a subject which can be covered in a broad manner during the course of our time together. Therefore, tonight we will discuss a little bit about the role of bacteria on the reef, and specifically to corals.

Most people think of bacteria in aquaria to be conveniently divided into the "good" bacteria and the "bad" bacteria. "Bad" bacteria include all those dreadful microbes who infect our fish and our corals. We hear little bits and pieces of such "nasties," bearing ominous names like Vibrio and Psuedomonas. Most of us who are keeping aquaria become aware of "good" bacteria when we initially learned about the importance of the nitrifying bacteria. Later, we may learn a little bit about the importance of the denitrifying bacteria. Perhaps a few will later delve into the subject of the fascinating reducing bacteria, usually if a black coloration appears and is noticed in the sand. We normally ascribe these foul smelling sulfur reducers to the "bad" bacteria designation.

But...........

Would it surprise anyone to know that in analysis of marine lagoonal sediments that:

• eighty different strains of denitrifying bacteria were isolated in sea grass rhizomes alone, much less the sediments?
• some bacteria actually denitrify *aerobically* in the sediments?
• the majority of the "good" denitrifiers are often the "bad" Psuedomonas, and also include "bad" Vibrios?

Might it be surprising to learn that in multiple analyses of healthy coral mucus that:

• more than 100 strains of bacteria have been isolated in single samples?
• corals actively culture bacteria in their mucus?
• the majority of bacteria normally present are "bad" Vibrios?

The Role of Bacteria in Coral Reef Ecology

Coral reefs depend heavily on bacteria in all manner of action. The majority of bacteria in the water column are free living and feed on dissolved organic matter. These microbes will process the organic matter in the water with a 30-50% efficiency rate. Pelagic bacteria can double their populations within one tide change to respond to an increase in nutrient levels. Bacteria normally compose between 5 and 20% of the total biomass of plankton, either free living in the water column, or associated with particulate matter. This number represents an even larger planktonic mass than zooplankton. They are also responsible for up to 30% of the primary production of reefs.

The "microbial loop" in the waters above and around a coral reef revolves around bacteria, organic matter, and the bacteriovores. This micro-food web is not only important in and of itself, but is also crucial in the maintenance of the phytoplankton populations. Because of the productivity of the reef organisms, there is a level of microbial substate produced by the flora and fauna that allows for bacterial productivity in the water column above the reef to be magnitudes of order above that in oceanic waters. As such, they may be responsible for 40% of picoplankton production and 25% of microplankton production. In other words, even in the water column, bacteria are the beginning and end of the plankton that feeds the coral reef. We can now see that the reef depends largely on the bacteria in the water column, and also that the water column bacteria and plankton depend largely on the reef.

The bacterial aggregates associated with particulate matter (detritus, phytoplankton debris, mucus, etc.) comprise only about 25% of the total bacterioplankton. Still, they enrich the particulate matter with their mass (termed "reef snow," or" marine snow"), becoming a very important nutrient source for coral reef filter feeders and planktivores. The important nutrient cycle that centers areound particulate matter and bacteria is termed the "detrital web." The nutritional aspect of bacteria to corals will be covered later.

If anyone thought that the importance of bacteria in the water was impressive, it is nothing short of trival compared to what happens in the sediments. If the aggregates of bacteria and suspended particulate matter are not consumed, they have a great chance of settling out on the sediments of the reef and the lagoon. Much of the waste material, algae debris, mucus and excess production from the reef is also drawn towards shore, where it settles on the soft bottoms. There, it fuels the growth of a diverse community of bacteria, detritovores, and other flora and fauna. They mediate the return of organic and inorganic matter back into the food web, provide for the decomposition of waste and decaying plant and animal matter, and allow for the beginning of new productivity by providing food and nutrients to algae and microfauna. Frequently, sea grass beds are found in areas of heavy organic enrichment. These true plants (not algae) are associated with some of the most highly productive communities on Earth. In and around their root structure, microbial production is as great as in any sedimentary community known. Even the productivity and decompostion abilities of the terrestrially enriched mangroves owe their effectiveness to bacteria and the community they sponsor. Perhaps surprisingly, mangroves are typically sources of limiting organic matter which are exported to the reef, rather than being consumers of it.

Lagoons and sea grass beds depend heavily on the organic matter produced by the reef, where the productivity of the bacterial community, by some estimates, equals or exceeds the gross productivity of the enitre reef itself! The upper one centimeter of lagoon sediments contain as much microbial biomass as all the water column above it. To further empahasize the immense capabilites of these areas, they are actually nutrient limited!! Here, bacteria are intricatly interwoven in the carbon cycle, the phosphorous cycle, and the nitrogen cycle. Most of the material exported from the reef is either utilized by the lagoon benthic communities for their own sustenance, or put back into the food web after decompositon, remineralization and processing. It then serves as a food material for the various polychaetes, sponges, ascidians, corals, bivalves, and plankton that inhabit the reef. A relatively small portion is either lost to the atmosphere or washed back into oceanic regions. However, the ultimate regeneration of nutrients is in their uptake into the reef community for growth and reproduction, They may also be indirectly incorporated into the nearly permanent reef structure itself by sustaining the metabolism of the hermatypic corals.

In summary, bacterial action and productivity is absolutely essential to the reef environment, and provides, arguably, the largest role in its success. Still, the primary nutrient which limits the bacterial populations is carbon. Adequate sources of carbon are largely provided by the success of the coral community. Once again, these two groups are wholely dependent on each other, and are inextricably woven together. The denser the coral growth, the more abundant the microbial growth. The denser the microbial growth, the more abundant the corals.

Bacteria and Corals

From the information presented above, it may no longer be a surprise that bacteria play an important role to corals. Indeed, this is the case. Bacteria comprise an very important trophic role in the heterotrophic needs of corals. Not only have we seen how they are common to the water column in which corals are bathed, but the mucus of corals happens to be an extremely good medium for bacteria growth. The level of bacterial productivity on coral mucus is at least one order greater than in the surrounding water. Paul (1986) even found levels on the coral surface to be seven times higher!

Mucus provides a nutrient broth of lipids, amino acids, sugars and other compounds that, in turn, provide abundant sources of carbon and nitrogen for microbes. Branching corals maintain higher bacterial counts in the spaces between branches. It has been hypothesized that these levels are controlled by the coral to some degree. There are many reasons why corals would prefer to maintain high bacterial levels that are not simply basd on their use as a mucus trapped food source. The bacteria present can work on particulate matter, dissolved organic matter, and even the mucus itself to potentially change some of the substances into forms more usable by the coral. Furthermore, the large number of bacteria may act as a "lure," attracting zooplankton that can then by captured by the coral. One step further, the larger zooplankton populations then provide corals with waste material from themselves and from the animals that come to feed on them. Protozoan grazers of the bacteria (who also get a bad ‘rep', but actually provide another important food resource to corals) actually help to maintain high levels of bacteria in the mucus through their grazing activities. Finally, bacteria secrete a number of antibacterial agents which may provide a level of immunity to the corals. This is commonly known among us humans as "probiotic." In fact, of 491 isolated strains of marine bacteria, both free living and animal associated, 126 produced antimicrobial compounds. The potential ability of corals to control the amount and composition of their mucus, and also to have it controlled by external factors, obviously has interesting implications in terms of coral immunity and health.

Indeed, corals do actively feed on bacteria in the mucus, in the water, and attached to particulate matter. They typically utilize them for 5% of their diet, by weight. This is on an efficiency level on par with many of the specialized filter feeders and sponges. Sorokin found that, in general, bacterioplankton ingestion alone can provide from 8-25% of the coral's respiratory demands. This amount is the equivlent of 1-10% of the animals total biomass per day...from bacterioplankton!! Its assimilation index by nutritional content is the equivalent to the nutrition acquired by the capture of small crustaceans (which are by weight, much greater and a greater energy expenditure to capture). Phosphorus, a normally limiting resource in coral reefs, is found in the cell walls of bacteria. Coral consumption of bacterioplankton provides them with a more easily assimilated source of phosphorous than from the uptake of inorganic phosphate contained in the water.

The degree to which any coral feeds on bacterioplankton is species specific, and depends largely on whether they possess ciliary-mucus filtering mechanisms. All surveyed corals utilize bacteria as a significant part of their diet, but some of the genera which depend to an even larger degree on this resource are Acropora, Pavona, Goniopora, Favites, Symphyllia, Leptastrea, Tubstraea, Seriatopora, Pocillopora, Montipora, Porites, Hydnophora and Turbinaria. Zoanthids are all very heavy consumers of bacteria. Soft corals and gorgonians also feed on bacterioplankton. However, compared to the stony corals, many do not produce similar amounts or compositions of mucus to enhance this ability . The xeniids and other soft corals with a heavy mucus coat, expectedly, consume more. Tubipora musica and certain small polyped gorgonians, including Mopsella, are also extremely proficient bacterial feeders.

Stress and water conditions, as well as diet, can change the composition of mucus. Such changes can then fuel the growth of other strains of bacteria that will preferentially utilize the new mucosal composition. In one study, over 100 strains of bacteria were collected from the mucus of Heteroxenia fuscesens and Platygyra lamellina. In this work, over 70% of the bacteria were found to be gram negative species. Vibrios comprised 46% and 57% of the total bacterial isolates, respectively. Another study with Heteroxenia and Palythoa showed a similarly high level (20-30%) of Vibrios in normal healthy coral mucus.

Bacteria and Coral Disease

One of the major obstacles in assessing causality to a specific bacteria in coral disease is that so many are naturally present on healthy corals. Their populations are great and variable, and they can depend on many factors. If a certain nutrient or stress is present at any given time, the resident mucus populations of a coral can become greatly changed. Such changes may be quite transient and quite normal. Thus, a coral with normally 50 strains of resident bacteria, under certain conditions, may be seen to have an unusually large accumulation of a specific strain. Given such variability, establishing a baseline of relative population levels on corals can be difficult. Furthermore, many of the bacteria that normally inhabit the coral surface are already potentially pathogenic. There are also many which are not; yet under stress, normally non-pathogenic bacteria may become pathogenic. Segel and Ducklow (1982) proposed a model by which coral disease can even be caused by the proliferation of resident bacteria alone. In such cases, without any bacteria necessarily causing direct harm, the activity and productivity of the bacterial mass can be so great as to affect coral metabolism/respiration to the point of disease. Rarer still are any diseases that are actually caused by a single agent. The net result is that a sick coral may or may not have a bacterial component to disease.

The recent articles in Aquarium Frontiers referred to the work of Laurie Richardson on star coral disease. In fact, this may be the very first disease known to be caused by a bacteria, though the work is still comparatively new. Anthropogenic influence and species specificity are both involved in this discovery, and perhaps there is even more yet to be discovered. Other coral diseases have all proved multi-causative, if a cause has even yet been isolated. In some cases, there seem to be bacterial components. In others, there is a tenuous association, or none. Tim Hovanec mistakenly associated bacteria and coral bleaching as a disease. Bleaching may or may not be a component of active disease, and bleaching is certainly not causative due to microbes in the vast majority of cases. Esther Peters, a coral histopathologist, informed me in a conversation that this particular bacterial association with bleaching occurred under unusual circumstances, as well. This is the type of information that leads to uninformed stereotypes of bacterial mediated disease. One or two cases of unusual and specific occurrences in conditions where other factors are already known to have played a role should not be cause for panic. Certainly, neither of these cases are even remotely likely to affect anyone keeping reef aquaria.

Relatively few problems or diseases of corals are actually attributable to bacteria. In truth, there may be diseases yet unknown and undiscovered that have a specific pathogenic microbial vector. However, there are many other organisms, including fungii, algae, sponges, and fauna which actually do cause coral disease or injury. Stress is far more likely to bring about active disease. Any of these factors may allow for normal bacterial populations living on corals, or present in the water, to become problematic. But, I believe it is very important to understand the conditions of bacterial growth and occurences in corals before assigning a "death to bacteria" call. Certainly, they are ubiquitous and of great importance to corals in many ways. As shown, the natural populations of bacteria present on corals can be responsible in actually directly and indirectly *preventing* disease. The degree to which this is applicable has yet to be determined.

Bacteria, Corals, and the Aquarium

At last we arrive to a practical application of this slew of information! How does this information about bacteria, corals, and coral reefs change our situation with keeping reef aquaria?

It troubles me knowing the lengths to which we go to eliminate bacteria in our tanks. Through much rumor, misinformation, and misunderstanding, we have allowed ourselves to be somehow mesmerized by deception. As a group, we tend to think that somehow we are able to maintian some vague populations of good nitrifying and denitrifying bacteria, but can then concentrate on eliminating the rest.... which certainly must be up to no good! Yet, we have learned that some of our good guys are potentially bad guys. And most of the bad guys are good guys.

When bacterial problems do arise, in fish or on corals, the attributable cause is normally an environmental parameter gone awry...a new specimen, poor water conditions, sediment disruption, and other stressors. Ordinarily, pathogenic action is under normal biologic control. Still, we purchase ozonators and UV sterilizers and turbo charged foam fractionators to rip all those bacteria out of the water column. Who needs ‘em, right? Corals, that's who! All the lovely bacteria...for the enriched "marine snow," and the antibiotics they produce, and their importance in the growth of other food sources......can we really afford to do this? And if we can, is it wise? What about our "sterilization techniques" prior to introducing corals. If these corals depend so heavily on normal bacterial populations in their mucus, why are we trying so hard to kill them? Perhaps we can hypothesize that things are "abnormal" prior to us obtaining them. To be honest, they probably are. But, water flow effectively reduces the thickness of the coral mucus and the coral surface microlayer....and is not stressful. Furthermore, we are not then eliminating, by bacteriocide, naturally occurring populations which may very well have been beneficial and normal to the animal. By applying a percentage of the previously mentioned probiotic study to the Platygyra study, we could potentially eliminate 26 species of bacteria which could have supplied natural antibiotic protection.

Lots and lots of diverse bacteria in our water, in our sand, on our rocks, and even on our corals is something desirable. This is how it should be. These microbes play an absolutely essential role, in all their biodiversity, in the function of both corals and the reef itself. Their importance in reef aquaria is likely even more important. We concern ourselves with the relative paranoia of a little voice that says "But what if they overpopulate, or what if I get a ‘bad' one? Isn't it better to be sure? Sterile is safe, right?"

I got some news for you, little voice!

They are already there!!!

If we can maintain a healthy tank, in balance, bacteria are our friends. If not, they can then become a problem. But the natural levels of any population, in contrast to artifically maintained sterility, will likely provide a better buffer than systems which are already running aganst what corals and coral reefs consider "normal." If we fail to maintain healthy conditions, or a balanced group of life, bacteria are only one of the many potential problems we face...no more, no less. If we affect certain species of bacteria, we potentially effect or alter a vast network of trophic webs, biochemically mediated events, and natural population control. These are likely of greater potential risk than pathogenic bacteria which, we must admit, are already present. Even when disaster strikes, it will ultimately be the bacteria who restore order to the chaos.

With that, I leave you all with the following quote:

"Reef scientists have flirted with the intricate feeding specializations and relatively simple dynamics of grazing food webs for long enough. It is time to deal with the less attractive and tractable questions of the sources, fates, and fluxes of dead and dying plant material and excrement...Whole coral reef ecosystems rather than covenient components must be considered, and natural or man-made gradients in forcing functions used to elucidate system function." Hatcher, 1983

Thanks everyone! :-)

Eric Borneman

Good current around corals has always been an accepted need it seems, and recently heard a talk on such stating this current allowed the corals to properly recieve nutrients from the water, In the actual Coral Reef there is natural current.I guess there is some balance needed here, your thoughts?

a balance? nopt sure I follow...a balance of what? Good cureent for maost species is essential...it provides increased metabolism, calcification, food import,e xport, etc...can't say enough about its importance!

So bacteria produce antibacterials, which help them to compete with others? Does that mean that is you get a bacterial infection, on the is not normal, then something has influenced the normal bacteria and allowed another one to get it?

but what balance are we referring to?

Could you say something about the toxicity of dinoflagellates in infecting SPS type corals?

There are way too many dinoflagellates to comment on...including the symbiotic ones *in* the corals. there are some species whihc do have toxic substabces that can smother or kill corals, but the ones which are common to our tanks are usually not the toxic type...snails seem to be most affected, IME

Should we limit the amount of bacteria loving creatures (zooanthlids,xenia etc) in our tanks to have a sucessful sps tank?

I don't think so. Bacteria tend to grow to their nutrient environment. I think most of our tanks, even the "nutrient starved" ones, have a pretty dense microbial level owing to the bioload in the tanks and the relative feeding load on a closed system. What I would be more concerned with is trying to eliminate the ones that are present

I recently had my top layer of live sand turn grey/black, followed by bright green and purple colors comming up from the deeper substrate. Then came a diatom bloom, and all my copepods seem to be gone. What have I done?

Good question.. There are prominent cyanobacterial mats that exist below the surface of the sand...they are important to nitrogen fixation and should be present in a mature sand bed...the grey black reducing areas may have caused a bit of local die off whihc the cyanobacterial mats then utilized...I think, given time, that should syabilize

So bacteria produce antibacterials, which help them to compete with others? Does that mean that is you get a bacterial infection, on the is not normal, then something has influenced the normal bacteria and allowed another one to get it?

I think that is one aspect that should be looked at, yes. I do not think *at all* that that is a sole cause. But given a "normal" level, anything that skews that level will be interpreted as a stress. I think the fact that some bacteria produce antibacterial, especially when you consider the numbers of bacteria present, may prove to have some effect. Probiotics are relatively new in human use...I think getting any real data on them for corals is a lon it is certainly something I think deserves consideration

Is there some balance that we could come to in using a skimmer and not stripping too much bacterial/planktonic material out of the water column, and still remove enough organic material that is present in our high load aquariums?

Yes, and I think that a lot of people are beginning to see the relative importance of that. I am not sure what that level is, or quite how is best to accomplish that, but I think it would depend largely on the individual tanks and what we are trying to accomplish...i.e. what species are present, what emphasis the aquarist is placing on the tank.
This is certain to be a hot topic in the future, methinks!

Could Eric comment farther on the statement "Perhaps surprisingly, mangroves are typically sources of limiting organic matter which are exported to the reef, rather than being consumers of it."

Mangroves are communties of exceptional productivity...BUT, they are largely prolific communities because of terrestrial inputs from land, soil, dropping leaves, etc this fuels the growth of the sponge and bacteria growth that makes them such good productive communities however, coral reefs are normally nutrient poor, and mangroves act more to provide some tof this organic material to them...they are largely not responsible for removing the waste matter of the reef sea grass beds and lagoons are primarily responsible for that in nature.

Have you read anything new about RTN, as to what kind of bacteria it *may be, what brings it about, and how to prevent/treat it?

I am fully convinced that what we call RTN is not caused by bacteria, but may have a bacterial componenet in *some* cases I think virtually *any* bacteria under the right conditions would be present in RTN corals, and have quite a bit of data to support that...

We buy UV Sterilizors and Foam Fractioners to rip these bacteria out of the water. Does this mean that it's better not to skim in a tank for the risk of reducing our bacteria levels to dangerous levels?

No, not really...merely that as a group, we try to maintain a level of sterility that I think can be counterproductive, and yes, I think that some of these devices are holding back well run tanks...they certainly have a place in water purification and in certainc ases..if you are comfortable with your tank, though, i think that the loss of particulates and other things from the water column, includiding bacteria, is not in the best interest of the nutritional needs of the animals we are keeping

Along the lines of the cyano bloom/copepod die off, now that the cyano is dead, will copepods come back?

I am certain that nothing short of a small thermonuclear detonantion would hold back the copepods! LOL

You say that there needs to be more care in collection and transport of corals. Do you think the recent problems with Elegance spp. corals are do to a bacterial infection or immunosuppression or just do to poor handling and storage?

Great question. I think that, in particular, that poor handling is largely responsible for this recent fragility of Catalaphyllia...this was a very hardy coral, but economies are not thriving around those countries where we are importing, and the number of reefkeepers and the demand keeps going up
as for the loss of tissue, and the type of recession, I would not be surprised if there was a similar mechanism going on in terms of stress and host cell adhesion...bu t that is purely a guess

Eric, to what degree is there evidence that bacteria form a major component of coral nutrition?

oh my gosh...tons...I used about thirty different papers on this presentation alone...if you are interested, email me and I will send you a list....if nothing else, do a literature search on Yuri I. Sorokin..he is a leader in nurtritional studies

Any thoughts on the long-term effects of using anti-bacterials in aquaria--mutations towards resistant strains.

yes, I think the use of long term antibiotics is an extraordinarily bad idea in fact, I think antibiotics are, in genreal, scary...the resistance of strains happens so quickly, and creating new ones is not something this planet needs more of

Would you describe RTN as being prevalent?

yes and no...I think it will become more prevalent as the weather warms up again...
RTN happens at such odd occasions, and the etiology of it is so mysterious
stir the sand, you get RTN sometimes
power failure...ooops RTN
new corals, RTN
bad supplier, RTN
sometimes you never see it, other times, it just happens
the real supposed prevalence of last year and the year before, I think, was mainly cause everyone was talking about it
I still see it as much in stores on certain genera as ever before
and I hear reports much the same
so , I think it is kind of dependent on the circumstances eb

Would it be theoretically possible to starve SPS and other sensitive corals by over-skimming bacterial populations in the water column? I ask because I skimmed hell out of my tank after a major dinoflagellate infection and now that it is in control, my SPS have starte bleaching...what do I do?

LOL...uh huh...I would suspect (jumping out on the limb here)
that you stripped enough out of the water column to cause an increase in light penetration but belaching is a very multi-causative problem
yes, I think you can starve SPS corals, in fact, I Know you can...not all SPS even have the theoretical capability of meeting energy budgets with light alone, and in practice, none really do...they all feed or uptake and not all amino acids are produced by photosyntheis
The corals, if just bleached, will repopulate so, over time, I think they will recover nicely.

Do we have a list available of species requirments from 1-10, as in jardini-10, so on, in terms of bacterial requirements?

That is a very complex issue.. I would refer the asker to contact me for a list of the literature...not all species or even genera have been studied...there are anomalies...mostly, the smaller polyped corals seem to feed more on bacteria...but then, Symphyllia, is also a big consumer...
The corals I listed in the chat were an accumulation of those which showed a higher than average bacterial consumption per mass per day all of them feed to some degree on abcteria , at least all that have been studied

How can one prevent the brown jelly disease, when corals turn into brown jelly

Brown jelly infections are largely bacterial and protozoan aggregates with a bunch of digested tissue thrown in for good measure it seems to occur in susceptible heavy mucus producing, heavy tissued corals usually after an injury or stress or if detritus settles, causing necrosis
I think good water conditions and strong water flow is the best preventative, but if you get brown jelly infections, I have found Lugol's dips to be a good treatment....I would not, however, advise that same dip as a preventative

What is your most highly recommended live sand suppliment?

live sand supplement? as in an additve? I am only aware of one! LOL and, IME, that one is a supplement, all right, but not sure I would add the previous adjectives to it <gg>
If I have misinterpreted the question, please catch me later or ask the moderator for a clarification

Can you hazard a guess on what you think the chemical may be? It seems that something must be producing it, if you place a RTN fragment in a healthy tank, it can spread to other colonies there in the new tank. If it was something in the source tank, then would it not be diluted to a very small degree? Could corals be very sensitive to it then?

Corals are capable of extremely acute chemical recognition cues...both in recognition of "enemies and friends", in response to certain foods, etc...they have a high degree of speicalization in this area, as would make sense in a crowded place like the reef with so much competition..the literature abounds with such descriptions...It is my hunch that corals are using a chemorecognition cue that, being in the water,, serves as a marker
As to the composition of such a chemical, I do not know...glycoporoteins have been implicated in some works... and in a closed system, given the sensitivity of these animals to such chemicals in the big wide ocean often many meters apart, our tanks are the equivalent of them being right on top of each other
I have a lot of thoughts on this, but I have more work to do before I go jumping off any piers here! LOL...thanks everyone :-)

how soon can you tell if the lugol's dip has a positive result on the coral?

fast...sometimes, depending on the degree of tissue loss, it can be harder to kill, but in my treatments with brown jelly, if I siphon off the mass by swishing inw ater before the dip (OUTSIDE THE TANK), I find that the jelly is gone after one dip if tank conditions are good