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EMeyer

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EMeyer last won the day on September 5

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About EMeyer

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  1. I've started a thread at R2R with some additional thoughts on this, motivated by the reading I've been doing on this bug. https://www.reef2reef.com/threads/a-recently-discovered-parasitic-bacterium-causes-disease-and-impaired-growth-in-corals.660413/ Here are the key things I want to highlight: It occurs in about 1/3 of wild corals sampled worldwide. It occurs in many genera that we keep as hobbyists, including Acropora, Montipora, Seriatopora, Stylophora, and Goniopora. It also occurs in anemones (including Aiptasia, as if you needed another reason to hate Aiptasia!) and Palythoa It causes White Band Disease in Acropora cervicornis. The pathogen can be transmitted by coral-eating snails, which also serve as a reservoir for the bacterium. The pathogen can also be transmitted through the water to injured corals. As someone who frags corals, this caught my attention. (Most interestingly of all) the parasite normally makes up a small part of infected corals' microbiomes, but nitrate enrichment leads to a bloom of A. rohweri and impaired coral growth in infected corals. Researchers hypothesize it directly steals ATP and amino acids from the host cells, sapping the host's energy. -Eli
  2. The presence is sediment samples may very well reflect its presence in micro invertebrates rather than a truly free living stage. The study is open access, available at https://www.nature.com/articles/s41396-019-0482-0.pdf As for species distributions, I'm embarrassed to say I scoured the supplementary info before I realized its shown right in Figure 7. Here it is - the corals and non corals where it is found, arranged in hobbyist terms. This is not all of them, just some of those commonly in the hobby. SPS - Acropora, Montipora, Pocillopora, Seriatopora, Stylophora, Porites LPS - Pavona, Turbinaria, Galaxea, Acathastrea, Cyphastrea, Favites, Platygyra, Leptastrea Soft corals - Rhodactis, Sinularia, Sarcophyton, Palythoa Anemones - Heteractis, Aipasia Its friggin everywhere. ... honestly, based on the ridiculously huge divergence times between these groups, I have to conclude this is as widely distributed in Cnidarians as Wolbachia is in Ecdysozoans, and potentially as important for understanding the biology of the group. This was a good time to get into aquarium microbiology, I think.
  3. They proposed a new species (rhoweri), genus (Aquarickettsia) and family (Midichloriaceae) for this bug. Within the order Rickettsiales, as you inferred. (Side note, see what they did there? Midichlorians.) I agree, Chloramphenicol and Doxycycline are on the list to try. They work for some other diseases in the rickettsiales. I read some suggestions that rifampicin and tetracyclin may be less harsh but all 4 are on the list. Most of these endosymbiotic bacteria are difficult or impossible to culture out of their hosts, but this bug is common in sediment too.Perhaps it is culturable. My hope is to get some infected coral, and infect an experimental tank or two with it. I have one wholesaler account, if you have some wholesaler contacts lets talk! Maybe we could split an order? I think wild imported corals are our best shot at getting our hands on this bug. since we have no data on its prevalence in tank corals but a big dataset showing its in 1/3 of wild corals... I have noticed odd behavior with wild zoas too (i.e. they sometimes have to adjust to captivity before they start growing explosively like tank raised zoas). I'm gonna check some of these too. If it grows in zoas it'd be trivial to culture, and since zoas are essentially immortal I'd rather grow it in them than acros. The study found it in multiple non-coral Cnidarians but I havent looked into which ones yet.
  4. Good question. Its found in lots of corals (51 different genera so far) but the best evidence is in Acropora. So SPS would be the most interesting. But really, anything that is also available in an aquacultured form would be useful. I have some wild vs cultured zoas I'm going to test and wouldnt mind adding to the sample.
  5. I want to follow up again in terms of possible treatments. This parasite is part of a newly proposed species, genus, and family... so we have to rely on information from close relatives. Fortunately the evolutionary relationships are pretty clear -- this is a close relative of the family Anaplasmataceae, which includes lots of other intracellular symbionts, parasites and pathogens. Because these cause a variety of diseases in animals and humans, there is some information on their sensitivity to antibiotics. I don't see anything terribly specific (i.e. these treatments will also kill some other bacteria). This makes them more suitable as dips rather than whole tank treatments. But several show potential, including some antibiotics available without a prescription if one is creative with sources (rifampicin and tetracyclin). If these can clear Wolbachia from an insect or nematode they should be able to clear Aquarickettsia from corals... easy enough to test once I find an infected coral...
  6. I've read parts of the R2R threads discussing this product but it would be interesting to get to talk to him in person. My two big questions: Has he published his theory anywhere? And what is in his product? I can find lots and lots of papers linking bacteria in the genus Vibrio with tissue lysis diseases in corals. They don't call it RTN, they have a variety of names like white syndrome. Working with advice from some microbiologists at OSU, a student of mine was able to repeat published methods for causing RTN using a cultured strain Vibrio. Having seen these effects in person, I can say -- thats RTN, in terms of the symptoms. I find it entirely plausible that there are multiple causes of tissue lysis in corals... maybe not all RTN has the same cause. But in terms of published studies, it seems to me the weight of the evidence points to one or more bacterial pathogens. But I remain open to data showing otherwise!
  7. This is an odd one! Is anyone importing corals? I would like to take a quick, non-invasive swab of them on arrival if so (pre-dip), to test their microbiomes. I am chasing a newly discovered parasite, which is present in 1/3 of corals worldwide. I am testing the hypothesis that this contributes to the observation that wild corals are not as hardy in captivity as aquacultured corals. We've detected it in some tanks in captivity. Now I want to know, is it more abundant in wild corals than tank-raised? (see this discussion for more details) If anyone is importing wild colonies these days, please get in touch... Thanks!
  8. Yeah, I've read a couple times and there is a lot more I havent digested yet, and I havent even touched the supplemental info yet. A few details I didnt see highlighted previously: The parasite A. rhoweri is found in 1/3 of corals sampled worldwide, in all oceans. It is also highly abundant in sand and reef sediments. It also occurs in other invertebrates. In corals, it is a true intracellular symbiont like the insects' Wolbachia. Its abundance is conclusively linked to nutrient enrichment (NH4, NO3, PO4). I didn't see any description of aquarium populations in their paper, but may have missed it. I think we may be the first to know that this is a thing for corals in reef tanks. I say again, I want to compare wild corals with aquacultured corals now! What if this contributes to the challenges of keeping freshly imported wild colonies? What if its because they, like so many wild corals, have this parasite and when placed in the high nutrient environment of a reef tank, the parasite kicks in?
  9. My concern is that there are many grades of stainless steel, and while many work well in freshwater, few or none are completely saltwater safe. I think only titanium is really inert enough for long term exposure.
  10. Its a great question. Since the discovery is so recent I am sure the specific answer is no. But the parasite has been classified, which gives us a lot of clues about what treatments are worth trying. I'm still digging into literature at this point. Thats why I can't wait to get this bug into one of my experimental tanks. Its been studied in the messy natural environment where you can't do proper experiments. The kind of clinical experiments we would benefit from are unlikely to get much attention from NSF funded researchers. But as soon as I can get my hands on an infected coral, we can start testing treatments.
  11. Hi everyone, Not sure if you've seen this article yet. Rebecca Vega Thurber and her team from OSU have discovered a new coral parasite and named it Aquarickettsia rohweri. A bacterium that lives symbiotically in wild corals, and in normal conditions doesnt appear to hurt anything. But in high nutrient conditions, it turns into a parasite and saps the corals' energy, leading to lack of growth and eventually mortality. https://www.nature.com/articles/s41396-019-0482-0 Hmm, I thought. High nutrient environments ... like a reef tank? I wonder if this is in any of our tanks.. Fortunately, DNA sequence based data make this an easy question to ask. I looked up a couple ID numbers in tables, I examined some BLAST reports, and here is the answer: 10%. Ten percent of the tanks we sampled (2 out of 20) had this bacterium. If I did not contact you directly today, your tank is not one of them. Good news! (I will ask please don't play public guessing games about which participants had this, since I want to leave peoples' data privacy up to them). I just thought I'd share this because its a great example of a bug with clear effects on coral health, and we now know it realistically does occur in aquariums in the Pacific Northwest. I didn't include my tanks in the first round. Now I can't wait to see if my problem tank has this! -Eli
  12. Please ignore, mobile issues that will take more troubleshooting than I have time for atm. More later!
  13. I am especially interested in your sample too, for that reason. It sounds like an important test case. And I've long suspected the various tissue lysis diseases in captivity are caused by bacterial infections like the white syndromes in nature (and the lab). What can we do about it? I think the answer has two parts. 1. On day 1? Honestly, nothing specific. I'm not aware of any medications with known active ingredients that are marketed for bacterial diseases of corals. This may sound pessimistic, but I'm not saying theres nothing to be done. Just nothing specific. But by analogy... if I ran an ICP test and found high levels of some uncommon contaminant (e.g. Sulfur). I'd likewise lack any specific remedies (sulfur specific resins?). But at least I'd know there was a water chemistry issue, and could take general actions aiming to correct water chemistry. (e.g. large water changes). On day 1 after identifying a bacterial cause, I think you'd be in a similar situation. No silver bullets, but at least a rational basis for large general actions to correct the problem. Sterilization of equipment, starting a new tank, then retesting for the presence of the (now known) bacterial pathogen before stocking corals. Thats not a trivial undertaking but it would provide a route to establishing a new tank free of the old bacterial problem. Thats better than just starting over and hoping for the best, I think. 2. Longer term (more than 1 day) ... there are huge numbers of antimicrobial medications available in the world of human and veterinary medicine. Some are very specific against known groups. For example, I am currently testing a compound that specifically inhibits Vibrios, based on lots of solid peer reviewed studies (just not studies about corals). The literature is full of similar examples. I think what has hindered the development of treatments for coral diseases has been lack of diagnosis. We describe things in terms of the speed of tissue loss or the appearance of the melted tissue, which makes it hard to develop hypotheses about treatments. Identifying a potential pathogen can immediately narrow the range of treatments to be tested. Just knowing theres a bacterial pathogen suggests antibiotic treatments, and the known differences in specificity among different antibiotics can further narrow this. Other compounds are so specific they aren't even described as general antibiotics, since they only affect particular families or genera. It won't take long after your data come in before we (the community) can test specific, evidence-based treatments targeting specific groups. I can't predict the future, but I think we're going to do a better job when we're able to base these treatments on microbial IDs and published data rather than herbal remedies
  14. Haha yeah, that is kind of my fear. Its hard to keep the content without keeping enough detail... and its details about DNA stuff, so I tend to nerd out.
  15. Then I will appreciate both of your feedback! Science communication is a funny challenge. There are multiple audiences one wants to reach, including both the professional scientists and reefers. After writing for academics for so long its an entertaining challenge learning to write for new ones.
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