Flatworms: The Good, the Bad, and the Pretty Terrifying--Part 2 and Conclusion

Seawitch

Water, water everywhere,
View Badges
Joined
Nov 3, 2018
Messages
1,740
Reaction score
3,968
Location
Vancouver Island
Seawitch submitted a new Article:

Flatworms: The Good, the Bad, and the Pretty Terrifying--Part 2 and Conclusion


A "red planaria" flatworm problem in a saltwater aquarium. Photo has been enlarged with a macro lens.

r2rredplanariaflatworm.JPG

Photo is from the Reef2Reef archives.

Welcome to the second part and conclusion of the flatworm article. For Part 1, just go here, but I warn you, it’s a long one.

As I mentioned last time, flatworms are a perennial topic in our forums because some marine aquarists have problems with them. I wanted to devote an article (or two) to aquarium flatworms and how we (try to) deal with them. If you need some help with your flatworms, head over to the Reef Aquarium Discussion forum, and you’ll find plenty of people willing to help you.

For this article, because there are so many references, instead of having tons of links within the article, I have grouped all the references together at the bottom.

So, last time, I left you hanging with the suggestion that Flatworm eXit (by Salifert), the most popular “reef safe” remedy for a plague of flatworms, is actually the drug, tetramisole HCL, a close relative of levamisole HCL, and that Flatworm eXit (I think) is roughly 1/10 the strength of tetramisole HCL.

And I told you a story about an aquarist that had a severe reaction while using Flatworm eXit and having a bare arm in the tank. Well, if you do the math, which I won’t bore you with here, it turns out that using Flatworm eXit in your tank is an extremely weak solution of tetramisole HCL—if it is tetramisole HCL which is not proven.

It’s highly unlikely that Flatworm eXit caused this person’s medical emergency unless the person was allergic to the drug or had a very strong sensitivity to it—which is possible but unlikely. So, was this aquarist having a reaction to flatworm toxins released in the tank? Or allergic to something else in the tank, totally unrelated to this whole flatworm discussion?

We don’t know, and we’ll never know. But if you use Flatworm eXit in your tank, I mean you’d probably have to drink a gallon of your tank water to be at risk from the drug, and the salt would probably kill you before the tetramisole HCL would. (I’m half-joking. Please do not do this at home.)

Regarding flatworm toxins, released when flatworms are killed, we don’t know if that’s true for sure either. We do know that there are plentiful studies showing that some marine flatworms contain tetradotoxin.

Tetradotoxin is a sodium-channel blocker, a potent neurotoxin, that’s found in many marine animals including several of the fish belonging to the order, Tetraodontiformes. This toxin is probably best known as the toxin you’re trying to avoid if you eat “fugu”, an Asian dish prepared from fish containing this toxin. Chefs, who prepare fugu, are required to be licensed following a strict, long, and draconian training and apprenticeship.

A fish from order Tetraodontiformes.
blowfish-609381_1920.jpg

Photo is a royalty-free image from Pixabay.

So, like I’ve said more than once—but it bears repeating—I don’t know if your flatworms contain toxins, but it’s definitely another good reason to wear gloves when you stick your hand in your tank, especially if you’re in the process of killing a ton of flatworms.

I don’t have a gas chromatograph at home or a laboratory or access to one. But if there are any biologists, analytical chemists, toxicologists, or other scientists reading this who would be interested in testing the aquarium saltwater following a treatment for flatworms, there are definitely plenty of inquiring minds who would love to know A) what Flatworm eXit is for sure and B) if there are any toxins released when flatworms die. Obviously, one test is anecdotal. A lot of tests on different aquariums would be super interesting.

It’s a notable coincidence that two products that do not tell you the ingredients, Salifert’s Flatworm eXit and Seachem’s Prime are both “reef safe.” Okay, I don’t believe in coincidences. In the saltwater aquarium business, there are very few products that are “reef safe,” and I think there is big money to be made on them. I understand the need for trade secrets and proprietary information. However, I have a problem with a company not willing to release this information in a medical emergency.

For DIYers, it’s possible to buy some of these antihelmintics as pure substances through many avenues: aquarium businesses, chemical companies, ebay, amazon, and through a veterinarian to name a few. Reef2Reef does not recommend buying chemicals through deepnet websites or from faraway countries where you can’t be confident that you’re receiving what you paid for. But if you’re going to try to dose pure chemicals yourself, then please be very careful to measure accurately—your aquarium livestock depends on it.

On another note, I asked a behavioral scientist I know, Dr. Rachel Grillot, to read these flatworm articles for her opinion on their readability before I published them. She immediately sent me a link to an article about a just-published study by a friend of hers about flatworm infections affecting the fecundity of women. If anyone doesn’t know what fecundity means, it’s fertility and ability to produce offspring.

Now this is a brand new study on a small population of women. We can’t possibly know if there are any conclusions to be drawn about other mammals much less fish. However, in closing, I’d like to mention that for those hoping someday to breed their marine fish, you might want to treat those fish for flatworm infections….or not.

A predatory *land* "hammerhead" flatworm, class Turbellaria and genus Bipalian.
photo_24957_20130521.jpg

Photo is a royalty-free image from freerangestock.com.

A special thanks is due today to the following individuals:

Tom Land, President Emeritus of the Washington D.C. Area Marine Aquarist Society, who spent a lot of time talking to me and discussing biochemistry. He is a treasure trove of information.

Rachel Grillot, Ph.D., who proofreads my articles for readability.

~~~~~~

We encourage all our readers to join the Reef2Reef forum. It’s easy to register, free, and reefkeeping is much easier and more fun in a community of fellow aquarists. We pride ourselves on a warm and family-friendly forum where everyone is welcome. You will also find lots of contests and giveaways with our sponsors.

References:

(1) https://en.wikipedia.org/wiki/Anthelmintic

(2) https://reference.medscape.com/drugs/anthelmintics

(3) https://www.reef2reef.com/threads/white-flatworms.85789/

(4) http://wetwebmedia.com/flatworms.htm

(5) https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1439-0469.2005.00301.x

(6) http://www.melevsreef.com/critter/benign-flatworm

(7) https://www.int-res.com/articles/meps/58/m058p041.pdf

(8) http://www.extreme-aquatics.com/707/saltwater/how-to-indentify-worms-in-your-reef-aquarium/

(9) http://wetwebmedia.com/WormPIX/FlatwormPIX/Flatworms2.htm

(10) http://wetwebmedia.com/flatworms.htm

(11) http://wetwebmedia.com/WormPIX/FlatwormPIX/Flatworms3.htm

(12) https://www.britannica.com/animal/flatworm

(13) https://biologywise.com/what-are-different-types-of-flatworms

(14) https://wamas.org/forums/topic/16160-dips-and-cures-red-bugs-to-acro-eating-flatworms/

(15) http://www.wetwebmedia.com/fltwmchemcont.htm

(16) http://www.melevsreef.com/articles/acropora-eating-flat-worms-aefw

(17) http://www.melevsreef.com/articles/how-to-eliminate-flatworms-red-planaria

(18) https://www.ccohs.ca/oshanswers/chemicals/ld50.html

(19) https://fscimage.fishersci.com/msds/32094.htm

(20) https://www.sciencedirect.com/topics/medicine-and-dentistry/levamisole

(21) https://www.jstage.jst.go.jp/article/suisan1932/52/6/52_6_1065/_article

(22) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5367013/

(23) https://www.sciencenewsforstudents.org/article/killer-flatworms-hunt-poison

(24) https://www.sciencedirect.com/topics/medicine-and-dentistry/anthelmintic

(25) https://reefs.com/magazine/pest-free-reefkeeping-iii-the-flatworms/

(26) http://www.salifert.com/?fbclid=IwAR3CynhuVQw61oeGRC0D-35uZzIUqm_Er-wxqvrnEcdHIFq0IG2DooMXvQs

(27) http://science.sciencemag.org/content/350/6263/970

(28) https://en.wikipedia.org/wiki/Tetrodotoxin

(29) https://pubchem.ncbi.nlm.nih.gov/compound/tetrodotoxin#section=Top

(30) https://www.bbc.com/news/av/magazine-18102811/preparing-fugu-japan-s-poisonous-fish-dish



Author Profile: Cynthia White

Cynthia received her BA in English from NYU during the Paleozoic Era. She has been a freelance writer and editor for over 20 years. She has written for newspapers and magazines, both in print and online and was formerly a marketing manager for a small oil company. Her portfolio can be found here. Now she is a writer and editor on staff at R2R, where her forum nickname is Seawitch. Her build thread can be found here.

For 15 years, she kept a dozen freshwater tanks, bred cichlids--Cyphotilapia frontosa--and sold them to pet stores in Calgary. Finally, after years of study, she has come to saltwater side. She lives in British Columbia, Canada, with her husband and three special-needs dogs, a five-minute walk from the Georgia Strait.
 
OP
Seawitch

Seawitch

Water, water everywhere,
View Badges
Joined
Nov 3, 2018
Messages
1,740
Reaction score
3,968
Location
Vancouver Island
Lol! Excellent article! Feels like reading a suspense thriller...
Haha honestly, that’s what I was thinking as I was writing it, but I’m not sure everyone will be as excited as us about flatworms. THANK YOU.
 

andrewkw

Valuable Member
View Badges
Joined
Jun 1, 2014
Messages
2,296
Reaction score
4,853
Location
Ontario, Canada
First of all great read, I do wish there was a part 3 dealing with polyclads which in my experience are much more troublesome in a reef then regular flatworms. They also kill snails, clams and a few other things where as the little guys as you covered aren't much of a thread on their own. I just finished up treating a tank with flatworm exit 10 minutes ago so I thought I'd share my thoughts.

I have used the product before but not for a long time 5+ years ago, maybe closer to 10. I am not so much worried about the flatworms wiping out the tank, but the allergic reaction story did give me some pause. As I said I have dealt with them before. This is in a simple 10 gallon nano reef - total time it took me was about 3hours maybe slightly more. If you are doing a full size reef I would devote a day or at least an afternoon to the project. Even the Salifert instructions state you should watch your tank for 6hrs after treatment.

I started by removing as many flatworms as I could. I did this 3-4 times. Every time after letting the tank settle more would show themselves. Again this is a nano tank so I was able to turkey baste basically the whole thing. To remove the bulk I used airline tube fed into a nylon filter sock and just kept adding the water back to the tank after I drained about 1-2 gallons. Doing this 3 times I removed probably close to 90% of the flatworms in the entire tank.

I then treated with the recommended dose and waited 40 minutes. I noticed some were still moving but the bulk were dead. Most when die turn black or at least darker. I then removed those ones and some water permanently. However I could see some still moving so I did another dose at 50% the original dose. I again waited 40 minutes and again more were dead. I removed these ones and stirred up the tank as best I could. I made sure to stir up the sand as I very easily could have knocked some under the surface and they may have found pockets of water to survive in.

I then proceeded to do a 60% water change and added some rox carbon. Again a couple dozen dead ones came up when I did the water change and this was after "getting every single one". There are no doubt dead ones still there but at this point the toxin should have been released and the large water change taken care of things. Back when I used the product in the past I also had to overdose to get rid of them all. I am still checking the tank frequently to ensure there are no alive ones. If I see even a single one I will dose another full strength regular dose. Even if I don't see anymore I may do another dose prior to the next regular water change. This is just to be sure I got them all. Getting them all is essential to eliminating them. I have seen various types of flatworms in pretty much all of my tanks but this is the first time I've had them get out of control in years. Likely the others were different species but this higher nutrient tank also proves a good breeding location for them. I will say I tried to remove them manually for months. This was essentially a waste of time in a small nano. In a regular sized reef this would be even more of a waste of time. While I could get rid of every single one I could see, if I did not scan the tank the very next day or at worst the day after that the cycle would start all over and in a few days the red plague would be back. Sure maybe a fish will eat them, or a nudibrach definitely will, but what are the odds he gets every single one before he starves to death? Even if the flatworm eating fish lives 10 years he may not eliminate them before dying as well.

To sum this up flatworm exit (or similar product) is the only solution I actually consider a solution. Everything else is a method of control. Respect it and the flatworm toxin but don't fear it. Spend the day doing it and you won't have to worry about them again until you reintroduce them somewhere down the line. This is also a good time to deal with other pests. I removed a bunch of bubble algae too. I probably should have taken more photos, especially since I was just reading part 1 of the article before this, but here is all the dead ones I got. I would estimate this to be less then 5% of the the total population in the tank. Since I got most of them alive the amount of toxin I released was also less then 5% and I really did not have to do such a large water change but again it's a nano. I will also note this is a fishless system and all the pods and mysid shrimp were unaffected by the treatment.

IMG_1101.JPG


The picture is not impressive, but again this is just a tiny fraction of the total amount. Think white filter sock turning red/orange..
 
OP
Seawitch

Seawitch

Water, water everywhere,
View Badges
Joined
Nov 3, 2018
Messages
1,740
Reaction score
3,968
Location
Vancouver Island
IMG_1101.JPG


The picture is not impressive, but again this is just a tiny fraction of the total amount. Think white filter sock turning red/orange..
Thank you for telling us this. That's very interesting. These flatworms definitely give me the heebie jeebies. I'll have a look at polyclads and see if I can come up with a piece on it.
 

andrewkw

Valuable Member
View Badges
Joined
Jun 1, 2014
Messages
2,296
Reaction score
4,853
Location
Ontario, Canada
I dug up this picture from 2010

polyclad.JPG


I had probably a dozen plus of these guys maybe more. I actually had them twice this was the second time. They took out quite a few snails, a small clam and back then I even had a sand dollar which is how I originally found them consuming him. He probably wouldn't have lived forever anyway but they certainly took him out before he ran out of food.
 
OP
Seawitch

Seawitch

Water, water everywhere,
View Badges
Joined
Nov 3, 2018
Messages
1,740
Reaction score
3,968
Location
Vancouver Island
I dug up this picture from 2010

polyclad.JPG


I had probably a dozen plus of these guys maybe more. I actually had them twice this was the second time. They took out quite a few snails, a small clam and back then I even had a sand dollar which is how I originally found them consuming him. He probably wouldn't have lived forever anyway but they certainly took him out before he ran out of food.
Oh dear. That's ugly. I'll see what I can find out about polyclads.
 

Subsea

Valuable Member
View Badges
Joined
Jun 21, 2018
Messages
1,945
Reaction score
3,028
Location
Austin, Tx
Thank you for the article. Very well written.

While unsightly at times, I have not found Red Planaria to be a serious problem, unless you are a wholesaler with Red Planaria in system. Bad for marketing.

In my many years in this hobby I have seen organisms develope immunity to treatment chemicals. In my 25 year old display tank, after three progressive treatments every two weeks for six week treatment period. I now have flatworm resistant Red Planaria in that display. When anything leaves that tank for transfer I use two stage treatment batch: 30 minute soak in 20 fold concentration of exit and then a 10 minute soak in 10% peroxide bath.
 

Where do you stand on water changes for your reef tank?

  • Regular Water Changes

    Votes: 359 61.4%
  • Occasional Water Changes

    Votes: 110 18.8%
  • Very Seldom Water Changes

    Votes: 49 8.4%
  • Water Change ONLY when there is an issue

    Votes: 48 8.2%
  • NO Water Changes Ever

    Votes: 19 3.2%

Online statistics

Members online
2,884
Guests online
6,272
Total visitors
9,156
Top