EMeyer Posted October 30, 2019 Share Posted October 30, 2019 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 3 1 Quote Link to comment Share on other sites More sharing options...
SuncrestReef Posted October 30, 2019 Share Posted October 30, 2019 Wow, that's interesting. Thanks for keeping us in the loop, and for taking the time to revisit your data. This shows how valuable your database is and will become as more discoveries are made! Quote Link to comment Share on other sites More sharing options...
pdxmonkeyboy Posted October 30, 2019 Share Posted October 30, 2019 Dude, this is for real cuting edge stuff! 2 Quote Link to comment Share on other sites More sharing options...
ibondy Posted October 30, 2019 Share Posted October 30, 2019 Is there any treatment for this parasite? Quote Link to comment Share on other sites More sharing options...
EMeyer Posted October 30, 2019 Author Share Posted October 30, 2019 8 hours ago, ibondy said: Is there any treatment for this parasite? 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. Quote Link to comment Share on other sites More sharing options...
SuncrestReef Posted October 30, 2019 Share Posted October 30, 2019 Here’s Eli with his new frag: 2 1 Quote Link to comment Share on other sites More sharing options...
albertareef Posted October 30, 2019 Share Posted October 30, 2019 Interesting that this bacterium becomes parasitic in high nutrient conditions where resources aren’t in theory limiting. Will have to read this study when I get a chance. Thanks for keeping us updated Eli! Quote Link to comment Share on other sites More sharing options...
obrien.david.j Posted October 30, 2019 Share Posted October 30, 2019 Eli, Thanks for continuing to flag interesting topics in this area. This is great! Doing a quick skim of the article made me realize I need to read it carefully. theres more to consume than just the charts. Quote Link to comment Share on other sites More sharing options...
EMeyer Posted October 30, 2019 Author Share Posted October 30, 2019 1 hour ago, obrien.david.j said: Eli, Thanks for continuing to flag interesting topics in this area. This is great! Doing a quick skim of the article made me realize I need to read it carefully. theres more to consume than just the charts. 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? Quote Link to comment Share on other sites More sharing options...
obrien.david.j Posted October 30, 2019 Share Posted October 30, 2019 Eli, While at MACNA, I met someone I think is controversial but might be interesting for this discussion. I've read threads on-line which argue his product is not real, arguments he charges too much for it ($50/dosage), etc... Didn't matter to me. I met the inventor of StopRTN and PreventRTN. We struck up a good conversation. He explained he's a Dr and he believes symbiont bugs in coral tissue is the cause of RTN/STN. And some events enable them to multiply aggressively, release into the tank, and eventually impact corals. I'm paraphrasing. He described his product as only able to kill bugs in the water column, and effectively only the surface layers of the corals. But there was no way to wipe out the ones in coral deep tissue. But his product knocks down the population, which matters. Sounds similar to the topics in this article to me. Oh, and I ended up bringing home some of his product. Haven't tried them yet. 1 Quote Link to comment Share on other sites More sharing options...
EMeyer Posted October 31, 2019 Author Share Posted October 31, 2019 48 minutes ago, obrien.david.j said: Eli, While at MACNA, I met someone I think is controversial but might be interesting for this discussion. I've read threads on-line which argue his product is not real, arguments he charges too much for it ($50/dosage), etc... Didn't matter to me. I met the inventor of StopRTN and PreventRTN. We struck up a good conversation. He explained he's a Dr and he believes symbiont bugs in coral tissue is the cause of RTN/STN. And some events enable them to multiply aggressively, release into the tank, and eventually impact corals. I'm paraphrasing. He described his product as only able to kill bugs in the water column, and effectively only the surface layers of the corals. But there was no way to wipe out the ones in coral deep tissue. But his product knocks down the population, which matters. Sounds similar to the topics in this article to me. Oh, and I ended up bringing home some of his product. Haven't tried them yet. 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! 1 Quote Link to comment Share on other sites More sharing options...
EMeyer Posted October 31, 2019 Author Share Posted October 31, 2019 (edited) 18 hours ago, ibondy said: Is there any treatment for this parasite? 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... Edited October 31, 2019 by EMeyer 2 Quote Link to comment Share on other sites More sharing options...
EMeyer Posted November 2, 2019 Author Share Posted November 2, 2019 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 3 Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.