Brown Jelly Disease: Under The Microscope!

[mcarroll]

Seems like a strong pathogenic effect is a much bigger driver here than stress. That's why I decided to go pathogen hunting rather than chasing down some hidden water quality boogey man.

I’m with you in thought and experience! Nothing I’ve done in the last 10 years has even put a funny look on the face of my mushrooms, let alone stressed them or kill them.

I can’t think of any other explanation for why no other coral in the tank would be susceptible while the stuff rampages through your mushroom patch, unless we think there’s a possibility that the stuff specifically targets mushrooms.

And if we really think that’s the case (we don’t), save that stuff and send it into production!!! I need some!

Very interesting experiments whatever the case!

 

[ChrisH]

I don't have answers, only observations and questions, but I thought to post these in case it triggers any ideas now or in the future. I chose this thread as the most comprehensive investigation that I've found out of the many, many postings I have read. Bear with the story as a setup:

I have a 2000 litre reef in two identical halves, 1000 litres in the garage where the skimming, filtering and stuff goes on, with water pumped back up through the floor to the display half (which is silent). It's been running, with changes to hardware, for around 35 years and the reef was gloriously wonderful. Most of it is automated for topup, lighting, feeding while away from home, but that's where it went wrong. A fuse tripped while away and it took out the power to the aquarium, both parts, for five days. Everything died; smelly, slimy mess on return home.

The options were to give up, try to start again and grow everything once more from small pieces. New power lines installed at huge expense, so they will not trip from some other factor. Ten days cleaning up meant a totally empty system, sand and media thrown away, a lot of rock cleaned very carefully with a toothbrush and rinsed (I had to try to save some rock, though dead coral was thrown away), with - surprisingly - seven red-leg hermits that made it through everything. New sand, bacteria, new water, new media and so on. Had to go away again for 2 weeks.

Returned to find the crabs doing fine and a few small polyps and xenia strands had appeared. Plus a lot of algae, so introduced some snails and increased phosphate removal. Water parameters are all fine, with slightly elevated phosphate (will be from the remains of material in rocks). Have a rock of polyps, new, which is doing well.

Then noticed brown jelly disease, which is why this seemed worth recording. All reports I've seen are concerned with saving a hard coral with an infection, with warnings not to let BJD spread. In this situation of mine, there is no hard coral, or skeletons of any old material. But BJD has appeared on rocks everywhere. My assumption is this is 'feeding' on material leaching from the rocks; there is little no surface organic material left after my scrubbing (well, there will be, but not any major amount).

My point being, BJD does not require live or dying hard corals to appear.

Treatment so far. Several times daily, removing jelly using a glass tube (I've used this method for years - glass tube about 5mm diameter hole, place near anything like BJD with a finger on the top end, remove finger and the suction is enough to pull the stuff into the tube; finger on top again and discard - once used to doing this, it is very fast and efficient). Using Brightwell Koral Recover - now on day 6 of a 7-day regime. The stuff is expensive and 'herbal' based - makes the water like milk for a while, and skimmers go beserk so they are turned off for the duration. Polyps, crabs, snails - no effect on these. Nor on the reappearing xenia and small polyps, which have survived somehow and are growing (and being ignoted by BJD). Likewise good corallina growth on rocks is still there, though BJD can cover this (sucking it off leaves good corallina growth underneath; it isn't damaged by the BJD)

Overall, the amount of BJD has decreased considerably. Of course, no way to tell if this is because I keep removing it, or because of the Recover (which is the only product I could find that stated in-tank treatment of BJD).

But observations in case it helps any investigation:

• As said, no hard corals or remains of these are in the aquarium, yet BJD is present and rife.
• It is fast growing, appearing on a rock that has been cleaned in around six hours, to the point it can be cleaned again
• It is virtually absent from the sump in the garage ... which has low lighting
• It is prevalent on rock surfaces facing the light in the display tank - deeper water, less growth or absent altogether. No appearance at all underneath rocks or in deep shade, so it seems to be light dependent
• It is sometimes easy to spot by a bubble of air/gas being produced; using the tube near a bubble always results in sucking out otherwise 'invisible' BJD

So I'm far from out of the woods, but some observations might help someone else.

And yes, totally upset at the loss of the original inhabitants. The oldest organisms had been with me for around 28 years. Like losing a friend.

 

[ChrisH]

It seemed worth an update on my report. First, I realised I had failed to mention that there is a lot of live rock in the sump, hence the importance of the observation that BJD was virtually absent there. In fact, I only ever spotted one small area, quickly cleaned. The sump is lit, but not to the same level as the display tank.

As of today, it is three days since I last managed to find any trace of BJD. I've made daily 5% water changes (the largest volume I can mix at a go), now decreasing to every other day for another week. Algae has almost gone.

As before I have no way of knowing whether this is because some parameter has changed that does not favour BJD, like an increase in blue component in the lighting or the loss of the residual phosphate. Or the mechanical removal each day, running out of the organic source it is feeding on, or the Brightwell treatment. Or a combination. But, it is possible to in-tank treat BJD, though I will wait for some time longer before adding any corals.

 

[andrewey]

First and foremost, our sincerest apologies to everyone for leaving you hanging!

It's been a few years since our last update and in the meantime we've had to balance performing all the necessary viability studies at different concentrations with our current medical education. For better or worse, Covid-19 has afforded us some more leisure time, so we finally have time to present the results of all of our testing over the last few years. An update with plenty of videos will be upcoming shortly- we're finishing the last round of testing right now with some of the most commonly suggested antibiotics.

 

[andrewey]

Before we get into the results of the experiments, a bit of a background is probably warranted. Brown Jelly Disease (BJD) is characterized by a brown, gelatinous mass that attaches to the flesh of infected corals. The “jelly” is associated with rapid tissue loss and the disease/jelly seems to spread swiftly to nearby corals. Unfortunately, the causative organism is poorly understood, although the disease is often characterized by large numbers of ciliates.


Although large numbers of these ciliates are associated with BJD (and other coral diseases including Brown Band Disease and White Disease), it is unknown whether they represent the primary infective organism of BJD, opportunistic pathogens feeding on an coral with depressed host resistance, or even “innocent” organisms consuming the necrotic tissue secondary to another pathogenic organism (e.g. protozoal or bacterial) or nonpathogenic disease. Much of the following testing was aimed at eliminating (or rendering non-viable) the ciliates with agents that would be non-toxic to the host corals. However, it is important to note that elimination of the ciliates may not necessarily be associated with increased survivability of infected corals.


To that end, agents were tested against their ability to decrease the mortality of the host coral. Because of the relative rarity of BJD events and difficulties inoculating healthy coral with the brown jelly, limited conclusions can be drawn from the non-statistically significant findings concerning mortality as we had limited samples to test on.


Lastly, it should be noted that some of the following treatments are not readily available to hobbyist reefers- their inclusion is simply aimed at trying to characterize the disease and the relative resistance patterns of the ciliate or causative organism. All of the following data should be treated as hypothesis generating only, we would not advocate any reefer attempt to treat their reef with any of the following agents. All treatments were conducted on isolated coral specimens, not on the host tank.



For anyone interested in further readings on the issues, the following are excellent background sources:

Sweet MJ, Séré MG. Ciliate communities consistently associated with coral diseases. Journal of Sea Research. 2016 Jul 1;113:119-31.

Sweet M, Bythell J. Ciliate and bacterial communities associated with White Syndrome and Brown Band Disease in reef‐building corals. Environmental microbiology. 2012 Aug;14(8):2184-99.

Ainsworth TD, Fordyce AJ, Camp EF. The other microeukaryotes of the coral reef microbiome. Trends in microbiology. 2017 Dec 1;25(12):980-91.

 

[andrewey]

Under the microscope

A sample of the jelly reveals that it's teeming with these ciliates. For every cubic centimeter of jelly, the ciliates numbered in the hundreds of thousands.

[40x]

As you can see, the ciliates are tube-shaped and regular in size.

[100x]


They have a tapered head and are surrounded by hundreds of cilia:

[1000x]

 

[andrewey]

As you can see, the cilia are longer at the head then the rest of the body. They use their tapered head to probe their surroundings before they advance.

The cilia move in tandem to propel the ciliate through the medium.

This will become important later, as some of the treatments seem to disrupt the ability of their cilia to work in tandem. As a result, the locomotion of the ciliate is disrupted and while appearing alive, the ciliate is unable to continue to consume any of the coral's zooxanthellae.





Under the microscope, the ciliates are translucent, although the contents of their food can be seen. In the previous videos, the green/brown spheres likely represent zooxanthellae from the coral they just ate!

Here is one of them that has not yet fed. This also demonstrates another one of their properties, the ability to squeeze through tight spaces.

 

[andrewey]

When food is plentiful (as in the case of an infected coral), these ciliates rapidly increase in number and reproduce sexually or asexually. We observed rapid increases in population density in many of the samples, which aligns with anecdotal evidence that BJD can kill a coral within a matter of hours. Here you can see ciliates dividing via binary fission.

The ciliates can rapidly pick a coral clean leaving only the skeleton and detritus in their wake. Once the flesh of the coral is consumed, the ciliates will seek out other food.

While the specific identity of the ciliates associated with BJD is still being investigated, the predominant species in the BJD samples we investigated possibly resemble a Philaster or Helicostoma species. However, other ciliates were found in the sample (as in the videos above). If there are any marine biologists reading that can help with IDs, feel free to weigh in!

 

[andrewey]

Experimental Protocol

Samples of BJD-infected coral were removed and placed in holding containers. Water parameters during all tests were as follows: Specific gravity 1.025-1.026, Temperature 78-78.2, pH 8.24-8.32, Ammonia 0, Nitrite 0, Nitrate 5-10, Phosphate 0.03-0.07, Alkalinity 8-8.1, Calcium 440-450, Magnesium 1420-1440.

For the ciliate tests, samples were removed from infected corals and placed in beakers containing 20mL of the host coral’s tank water. Serial dilutions of each agent were utilized to determine time course and lethal dose to both the ciliates and host tissue. The samples of the brown jelly were not homogenoized to mimic real world testing conditions (ability of the agent to penetrate the jelly and treat underlying coral).

Infected specimens were predominantly from colonies of Caulastraea, Euphyllia, and Acanthastrea. These results may not be applicable to other LPS, SPS, or softy species.

 

[andrewey]

Metronidazole

Metronidazole (flagyl, metroplex). Readily available to hobbyists as metroplex, this antibiotic has great anaerobic coverage and limited activity against protozoa. Pharmaceutical grade metronidazole was used as an analog for Seachem’s Metroplex (active ingredients for metroplex report 70% metronidazole). Normal dosages for Metroplex are 1-2 scoops per 10 gallons, equivalent to 125mg/10 gallons. This dosage is usually given multiple times over several days, but given the rapidity of BJD, it seemed prudent to test dosages that were able to slow tissue destruction or ciliate activity in a shorter interval.

Concentrations tested: 0.33mg/dL (equivalent to metroplex dosage of 125mg/10 gallons), 0.03mg/dL, 0.66mg/dL, 3.3mg/dL, 6.6mg/dL, 33mg/dL. Time course: 1, 5, 15, 30, 120, 240 minutes.


Results:

No appreciable reduction in ciliates at 0.03 and 0.33mg/dL (metroplex and 10-fold dilution of metroplex concentration). Limited slowing of cilia at 0.66mg/dL with increasing mortality at 3.3mg/dL and 6.6mg/dL. No noticeable increased mortality in the ciliates at 33mg/dL compared with 6.6mg/dL, however we did observe increased bleaching of samples of coral tissue at 33mg/dL (100 times suggested dosage). Reduction in viable ciliates was loosely associated with an increasing time course, but none of the tested concentrations or time courses were able to kill at least 50% of the ciliates in both samples (one sample had elimination of ciliates after 60 minutes at 6.6mg/dL, but this result was not reproducible in two additional tests).

Ciliate activity after 60 minutes at 6.6mg/dL


Two heads of C. furcate (candy cane/trumpet) were rinsed in fresh saltwater to remove as much of the brown jelly as possible before being treated with either 3.3mg/dL (Equivalent to 10 times suggested dosage of metroplex) or 6.6mg/dL (equivalent to 20x dosage) for 60 minutes. The treated specimens were placed in fresh experimental tanks utilizing fresh saltwater and mature biological filters from a non-infected tank. All water parameters were identical to their original tank. Both heads died within 12 hours and were devoid of flesh by 48 hours.

Takeaway:

None of the tested concentrations or dip times were able to eliminate over 50% of the ciliates. Further investigate may investigate higher concentrations of metronidazole, however increased bleaching of coral tissue was seen at 33mg/dL (100 times the normal dosage). Whether or not this bleaching represents permanent or transient injury to the coral was not investigated. Further investigations may assess whether repeated dips at a lower concentration are more efficacious. At present, Metronidazole does not seem to be an effective agent at eliminating the ciliates associated with BJD.

 

[andrewey]

Lugol's Solution


Lugol's iodine, readily available to hobbyists is a common disinfectant used in the aquarium industry. A combination of potassium iodide and iodine, lugol’s has a wide antimicrobial spectrum and is an effective bactericidal, fungicidal, and virucidal at proper concentrations. Often used as a coral dip at a concentration of 40 drops per gallon of saltwater (2mL of lugols in ~38dL saltwater).

Concentrations tested: 4 drops/gallon, 40 drops per gallon, 80 drops/gallon, 400 drops/gallon, 4000 drops/gallon. Time course: 1, 5, 15, 30, 60 minutes.


Results:

Ciliates seemed to be unaffected at 4 and 40 drops per gallon at every time course. Roughly 5 and 10% of the ciliates were slowed at 80 and 400 drops/gallon, respectively (following dips of 15 minutes). Greater than 50% of the ciliates had disruption of their activity at 4000 drops/gallon (100x normal dipping concentrations). Additional mortality of ciliates was noted at 30 and 60 minutes compared with 15 minutes, but subjective toxicity to the coral tissue was observed with increasing dip times.

[Ciliate activity after exposure to 400 drops/gallon for one hour]

Four heads of BJD-infected C. furcate (candy cane/trumpet) were rinsed in fresh saltwater to remove as much of the brown jelly as possible before being treated with either 400 drops/gallon or 4000 drops/gallon for 15 minutes. The treated specimens were rinsed with fresh saltwater and placed in separate experimental tanks utilizing a mature biological filter from a non-infected tank. All water parameters were identical to their original tank. Of the two heads treated with 400 drops/gallon (10x normal dipping concentrations), one head survived to 7 days before perishing and the other head was devoid of any remaining tissue within 72 hours. Both heads treated at 4000 drops/gallon died within 24 hours.

Healthy control heads of C. furcate (sourced from a non-infected system) were unaffected by 15 minute dips of 4, 40, and 80 drops/gallon. One healthy control slimed heavily at 400 drops/gallon and made a full recovery, but only after two weeks. One control head tested at 4000 drops/gallon perished within 48 hours, so a second control test was not performed.

Takeaway:

A concentration of 4000 drops/gallon was necessary to demonstrate at least 50% disruption of ciliate activity. While both infected coral specimens exposed to 4000 drops/gallon died within 24 hours, it is unknown whether their death was secondary to exposure to lugol’s at such a high concentration or secondary to the infection. Unfortunately, a larger sample size would be necessary to determine whether 4000 drops/gallon is toxic to healthy corals. At present, all that can be suggested from the limited observations utilizing Lugol’s is that dips up to one hour at 10 times normal concentrations do not seem to be overwhelmingly effective at reducing ciliate activity.

 

[andrewey]

Macrolides


In general, macrolide antibiotics are used for the treatment of upper respiratory or skin and soft tissue infections. They have decent coverage against gram-positive bacteria, limited efficacy with gram-negative bacteria, very limited effect on eukaryotes, and increased coverage of “atypical organisms”. To my limited knowledge, macrolides are not readily available to hobbyists, with the exception of erythromycin, which can be found in products such as API’s E.M. Erythromycin.

Although not readily utilized as a coral dip, API’s E.M. Erythromycin utilizes an in-tank dosage of 200mg/10 gallons (a total of four doses every 24 hours). This dose (200mg/10 gallons), as well as concentrations of 200mg/gallon (10x), 2g/gallon (100x), and 20g/gallon (1000x) were tested.

The macrolides Erythromycin, Azithromycin, and Clarithromycin were all tested at the above concentrations for dips of 1, 5, 15, 30, 60, and 240 minutes.


Results:

Ciliates were unaffected by all three antibiotics at doses of 200mg/10 gallons and 200mg/gallon at every time point. A reduction in non-ciliate activity was noted at doses of 2g and 20g/gallon, although ciliate activity was unaffected at these doses at every time point.

[Ciliate activity following six hour exposure to 20g/gallon Azithromycin]

[Ciliate activity following six hour exposure to 20g/gallon Erythromycin]

Four heads of BJD-infected Euphyllia divisa (frogspawn) were rinsed in fresh saltwater to remove as much of the brown jelly as possible before being treated with either Azithromycin or Clarithromycin at concentrations of 2g/gallon or 20g/gallon for 60 minutes. The treated specimens were rinsed with fresh saltwater and placed in separate experimental tanks utilizing a mature biological filter from a non-infected tank. All water parameters were identical to their original tank. All four heads died within 48 hours and were devoid of flesh within 96 hours.

Two healthy control heads of C. furcate (sourced from a non-infected system) were unaffected by 60 minute dips of 2g/gallon of Azithromycin or Clarithromycin.

Takeaway:

Unfortunately, there are some severe limitations in our testing of macrolides. First, while we tested three of the more common macrolides (azithromycin, erythromycin, clarithromycin), we were unable to test every antibiotic in this class. Secondly, we were unable to infect healthy heads of Euphyllia during this series of experiments. As a result, the control utilized in this case was of a different species (C. furcate). As with all of these experiments, given the monetary cost of setting up enough experimental tanks and sacrificing LPS specimens, the number of trials is far short of anything that could be called conclusive. That being said, based on the ciliate activity at up to 20 grams/gallon, it seems unlikely macrolides are an effective strategy for treating the ciliates associated with BJD.

 

[taricha]

@andrewey very cool to see you jump back in on this.

Although large numbers of these ciliates are associated with BJD (and other coral diseases including Brown Band Disease and White Disease), it is unknown whether they represent the primary infective organism of BJD, opportunistic pathogens feeding on an coral with depressed host resistance, or even “innocent” organisms consuming the necrotic tissue secondary to another pathogenic organism (e.g. protozoal or bacterial) or nonpathogenic disease. Much of the following testing was aimed at eliminating (or rendering non-viable) the ciliates with agents that would be non-toxic to the host corals. However, it is important to note that elimination of the ciliates may not necessarily be associated with increased survivability of infected corals.

To that end, agents were tested against their ability to decrease the mortality of the host coral. Because of the relative rarity of BJD events and difficulties inoculating healthy coral with the brown jelly, limited conclusions can be drawn from the non-statistically significant findings concerning mortality as we had limited samples to test on.

Did you see this paper that (to me) seemed persuasive on the bacterial cause, and the ciliates as incidental?

"Experimental antibiotic treatment identifies potential pathogens of white band disease in the endangered Caribbean coral Acropora cervicornis"
This paper from 2014 is pretty dang great. Some quotes pulled from article.

• ... WBD [White Band Disease] is amenable to treatment with either ampicillin or paromomycin sulfate
• WBD is, in fact, a transmissible disease attributable to a 0.22–0.45 µm filterable fraction that was susceptible to antibiotic treatment. (likely Gram Positive Bacteria)
• we conclude that WBD is caused by microorganisms rather than by physiological stress.
• This study also shows that WBD, and other diseases such as WS [White Syndrome], white plague, and black band disease is a polymicrobial disease associated with a number of specific microorganisms that are consistently associated with diseased samples but absent, or undetectable, in healthy ones.
• One of these, the ciliate Philaster lucinda (KC832299), has recently been shown to be consistently associated with the coral disease WS in the Pacific [17] and within aquaria [28], which all have identical disease signs. (this is the ciliate that is characteristic of Brown Jelly)
• However, selective elimination of [ciliate] using metronidazole failed to arrest disease lesion progression in controlled experiments...
• However, ...analysis showed that the ...disease changed in the metronidazole treatment. This result is consistent with this ciliate being a secondary pathogen which nonetheless contributes to the typical pathogenesis of WBD and WS. (The ciliate's presence/absence determines the look of the disease.)
• Is a combination of more than one of these three potential primary bacterial pathogens required to maintain the disease state, although all three plus the ciliate consistently co-occurred in the disease in nature?

Also in this post I found that Doxycycline looked really interesting in wiping out bacteria and arresting BJD on soft coral cutting overnight. Where erythromycin and metro (in-tank) did nothing notable.

On to the 4 beakers: Control (nothing), Chemiclean, E.M. Erythromycin(API), and API Fin and Body Cure (Doxycycline hyclate)
...
I was amazed at how clean and almost totally jelly-free the cuts in the Doxycycline were, I put it under a scope to look closer.
...
super clean - no noticeable tissue degradation at the cut site. almost totally Brown Jelly free.

At that point I ran out of Brown Jelly to test, so one interesting beaker and no wider conclusions.

 

[andrewey]

That 2014 paper by Sweet is a really great paper- I hadn't read it in a few years! Personally, I'm not entirely convinced that bacterial are the causitive organism in these disease (or to what extent the death of the coral is primarily from bacteria). From those coral researchers I've talked to, it still seems to be pretty controversial what percentage is attributable to bacterial infection vs ciliate infection. Obviously the issue is pretty complex given both the diversity of infected corals as well as the usual microbiome of different locales.

For example, a follow up paper by Sweet two years later seems to muddy the waters a bit in my mind:
Sweet MJ, Séré MG. Ciliate communities consistently associated with coral diseases. Journal of Sea Research. 2016 Jul 1;113:119-31.

Other examples of this muddying include
Randall CJ, Jordán-Garza AG, van Woesik R. Ciliates associated with signs of disease on two Caribbean corals. Coral Reefs. 2015 Mar 1;34(1):243-7.

That being said, one of the really interesting bits that gets overlooked is that BJD has only been reported in aquaria! Therefore it remains to be seen whether BJD is analogous to WBD, WS, or other diseases or whether it represents a syndrome with a different etiology altogether!


As far as doxycycline is concerned, we weren't able to test any of our samples with any soft corals. We still have some cilliates we're "culturing" and performing tests on, but all of our tests were run on LPS. Fascinatingly, doxycycline was ineffective at killing the ciliates in our tests, nor was it able to stop tissue desruction of two species of LPS in our tests (full write up to follow). I wonder whether that reflects differences in host defense between softies/LPS or is a reflection of small sample size?

 

[andrewey]

Bayer Insecticide

Commonly used as a coral dip, Bayer Advanced Complete Insect Control has two active ingredients, Beta-cyfluthrin, a pyrethroid toxic to invertebrates, and Imidacloprid, a CNS insecticide. While there seems to be a range of effective concentrations, most reports suggest concentrations of 1 part in 20 to 1 part in 10 (e.g. 1.5mL of Bayer in 1oz tank water, 10mL Bayer in 4 oz of water).

Concentrations of Bayer to saltwater of 1 in 20, 1 in 10, 1 in 5, 1 in 2, and 1 in 1 were tested. Time points of 5, 10, 15, 30, and 60 minutes were tested.

Results:

Ciliates were unaffected at every concentration of Bayer insecticide dip, even at dips of 1:1 for 60 minutes. Due to the complete lack of efficacy of the Bayer dip, only two healthy control heads of C. furcate were dipped for 15 minutes at concentrations of 1 in 5 and 1 in 2. Both heads tolerated the treatment well.

[Ciliate activity following 60 minute exposure to 1:1 Bayer to water]

Takeaway:

As far as the ciliates are concerned, the Bayer Dip was ineffective at all dosages. Further experiments may test whether infected specimens recover from BJD following Bayer treatment via mechanisms unrelated to ciliate mortality. At present, it seems unlikely Bayer is an effective dip for treating the ciliates associated with BJD.

 

[taricha]

For example, a follow up paper by Sweet two years later seems to muddy the waters a bit in my mind:
Sweet MJ, Séré MG. Ciliate communities consistently associated with coral diseases. Journal of Sea Research. 2016 Jul 1;113:119-31.

Other examples of this muddying include
Randall CJ, Jordán-Garza AG, van Woesik R. Ciliates associated with signs of disease on two Caribbean corals. Coral Reefs. 2015 Mar 1;34(1):243-7.

Excellent. thanks for the more recent papers, I'll check them out.

That being said, one of the really interesting bits that gets overlooked is that BJD has only been reported in aquaria! Therefore it remains to be seen whether BJD is analogous to WBD, WS, or other diseases or whether it represents a syndrome with a different etiology altogether!

Is it that BJD is basically only a term in the aquarium hobby (my impression), or are you saying the actual presentation and symptoms of BJD aren't reported much outside aquaria?

 

[andrewey]

@taricha

As far as I've read, it would seem that the presentation/symptoms of BJD has never been reported in a wild colony and is completely restricted to the aquarium hobby.

There does not seem to be an analog in the wild to the disease- the closest disease seems to be brown band disease (mostly based on the ciliates). That being said, I'd love if any Marine Biologists/hobbyists chime in and correct any misinformation! It seems coral diseases in general are poorly characterized and the etiologies of many have not been concretely identified.

 

[drawman]

Since you tried Bayer I'm curious if you used Melafix...

 

[andrewey]

@drawman I have not tested Melafix yet. I have a few more tests lined up, but I'll add it to the list if I can get my hands on some- thanks!

I know it's not a perfect parallel, but I I did test tea tree oil, the oil from Melaleuca alternifolia (the active ingredient in Melafix is from Melaleuca leucadendra). I probably won't do a long write up on tea tree oil, but it was ineffective at most doses and at doses that were effective at killing the ciliates, the coral was also killed.

 

[drawman]

@drawman I have not tested Melafix yet. I have a few more tests lined up, but I'll add it to the list if I can get my hands on some- thanks!

I know it's not a perfect parallel, but I I did test tea tree oil, the oil from Melaleuca alternifolia (the active ingredient in Melafix is from Melaleuca leucadendra). I probably won't do a long write up on tea tree oil, but it was ineffective at most doses and at doses that were effective at killing the ciliates, the coral was also killed.

I know a lot of people report coral death at dips longer than 5 min FYI when/if you do test with Melafix . I personally do 5 minutes with no issue.