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FAQs about Flatworms, Including " Planaria" 2

Related Articles: Flatworms (incl. Planaria), Pest Flatworm Control by Anthony Calfo, Worms, Featherduster Worms

Related FAQs: Flatworms/Planaria 1, Flatworms 3, & FAQs on: Flatworm Identification, Flatworm Behavior, Flatworm Compatibility, Flatworm Control, Predator Control, Chemical Control, Flatworm Selection, Flatworm Systems, Flatworm Feeding, Flatworm Disease, Flatworm Reproduction, & Worms, Worm Identification, Fire/BristlewormsInvertebrate Identification

Waminoa sp. on Euphyllia ancora, N. Sulawesi where it is found on many cnidarians. 

Flatworms on my Corallimorpharia 1/5/07 First, happy new years to everyone at WWM. <And to you.> My Corallimorpharians are covered in flat worms similar to the pic in the article,  "Flatworms, including "Planaria" & Marine Aquariums" by Bob Fenner, on your website.   In the article Bob recommends leaving them alone or getting a predator.  <I actually prefer manual removal over getting a predator, most find something better to eat in the tank than the flatworms.>  They do not appear to be harming the mushrooms however can I remove the rock the Corallimorpharians are on and give it a fresh water dip?  <Would hurt/kill the corals.>  If not, or also, what type of predator would you recommend.  <A siphon during water changes. Otherwise 6-line wrasse are sometimes a good choice.> I have a 100 gal tank with 1-yellow tang, 1-regal tang, 1-blenny, 2-maroon clowns and two-Banggai cardinals.  The tank is 6-months old and is doing well: sg-1.026 kh-12 cal-420 nitrates-0 phos low Thanks again. One additional thing I failed to mention, which may affect the choice of a predator, is that I have 2-cleaner shrimp. <A possible problem with the six-lined wrasse, although often works out fine.  My suggestion is to go with manual removal during water changes.  The worm's population will often wax and wane over time..> <Chris>

Flatworm Obliteration 12/24/06 Good Evening everyone, <Evening> I've got a problem...one that can't be solved with yelling anyways.   <The toughest type.> I have flatworms....and I have for quite some time.  At first I used Salifert's Flatworm Exit, <Personally not a fan of this product> and it worked, to a degree.  However, against my vocal discharge, they came back.  <They usually do.>  Then after reading the WWM forums, I decided to get a yellow wrasse.  While I knew I certainly had the ability to handle his bioload and he is quite a pretty fish, he happens to be as ineffective as me when it comes to removing these pests.  <Better stuff to eat.> Here in a nutshell is my tank so that you have some background info 100g long (5' long) 120 lbs Live rock 14g sump 14g refugium ASM G2 Skimmer Phosban Reactor w/ half carbon half Kent Phosphate Remover Nitrates  0 Nitrites   0 PH        8.3 Salinity  1.025 Calcium  425 So now my question.  What can I do?  Is there anything short of hypnotizing myself and learning to love my red flat bodied buddies left?  They apparently love me, but I'm afraid the relationship is quite one sided.  Any help would be appreciated. <Best bet is to just accept them into your life.  Beyond manual removal during water changes and keeping nutrients as low as possible not much to be done.  Their populations tend to wax and wane over time.> Regards, Clay <Chris>

Red Flatworms 10/5/06 Hello Crew, <Hi> I have a case of red flat worms.  Multiplying rapidly. <Not uncommon.> 24 gallon nano 25lb live rock 4" DSB nitrate undetected phosphate .02 mg 1250 ca  410 dKH/alk 9.7 temp 77.5-79 F .0025 salinity <Probably 1.025> remora nano skimmer PhosBan ChemiPure chiller 150 20k HQI halide pendant Healthy 1 year old bubble tip anemone hosted by 2 ocellaris clowns sally light foot serpent star critters mushrooms zoos What natural predator in such a small tank will help.  I DO NOT want to medicate this beautiful system! Best, Ronnie Shingelo <There are no reliable predators for these that are appropriate for this tank.  However siphoning them out during water changes and frequent use of a turkey baster to dislodge them you get their population under control.> <Chris>
Red Flatworms 10/7/06
I did siphon out a lot today, but there are so many on the rocks.  The more I look the more I see.  Will they eventually die off? <Mostly>  What if I borrowed my friend's wrasse for a few weeks?  Or a scooter blenny?  <More trouble than it is worth.> Thanks so much for your time! Ronnie <Chris>

Help with Acro Eating Flatworms   8/19/06 I just discovered the eggs and subsequently the actual flatworms on what we call here a New England Aquarium Acro (It's very similar to the famous purple tip Larry Jackson coral that many know about, yet with thinner and more numerous branches).   I decided to check the coral because it was bleaching near the base and had fairly poor and splotchy coloration in general. My question is: How do I treat these buggers and has anyone found a way to kill the eggs?   <What little I know re is summarized, posted here: http://www.wetwebmedia.com/pestflatwrmanthony.htm and the linked files above> I have heard that the Levamisole treatment that is being used usually kills the coral before breaking the AEFW life cycle.   I have also heard on RC that Betadine dosed into a dip treatment tank at 3ml/liter of SW is having success in Europe. <I have heard this as well>   I can afford to replace these colonies, but there is a desire to preserve the life I have nurtured all this time and to learn as much as possible so that I can share this info with others.  I currently plan to remove all Acro colonies to a QT tank and attempt the Betadine dip weekly until I do not see any worms on corals or eggs on their bases. I am hoping that one of you may have had experience with these and may be able to help me find a safe and effective QT and treatment method to prevent the reinfestation of my tanks. Thank in advance, Mauro DiBenedetto <Do please follow up with your observations. Bob Fenner>
Re: Help with Acro Eating Flatworms   8/20/06
>  I have heard that the Levamisole treatment that is > being used usually kills the coral before breaking the AEFW life cycle.   > I have also heard on RC that Betadine dosed into a dip treatment tank at 3ml/liter of SW is having success in Europe. > <I have heard this as well> >   I can afford to replace these colonies, but there is a desire to preserve the life I have nurtured all this time and to learn as much as possible so that I can > share this info with others.  I currently plan to remove all Acro colonies to a QT tank and attempt the Betadine dip weekly until I do not > see any worms on corals or eggs on their bases. I am hoping that one of you may have had experience with these and may be able to help me find a safe and effective QT and treatment method to prevent the reinfestation of my tanks. > Thank in advance, > Mauro DiBenedetto > <Do please follow up with your observations. Bob Fenner> Bob, Minor update:  I tried the Betadine dip at 3ml/Liter on that NE Aq Acro.  Almost immediately the worms dropped off the coral.  At 23 minutes they appeared very dead. At 25, a puff of a turkey baster rendered the worms into fleshy dust. <Good... time to move them...> The game plan is to pull all Acros and put them in a 20long with a bare bottom and no rock. <Ahh, very good> I plan to dip all of these corals in the Betadine solution and quarantine them for the next month, treating them weekly to make sure I get all of these worms.   I plan to empty the 20long and clean it thoroughly before reintroducing the treated corals.  If I see any worms during treatment, the protocol will be extended by another month. In the interim the 180 display, which thankfully has not had any Acros encrust within it will lay fallow of Acros for the next 45-60 days to ensure any worms I introduced will be dead.  (I can be sure there are no hidden Acros because I just set up this tank and had only moved over a 2 Acroporids before finding the flatworms in my tank. <I see> All my best and do drop a line to the Boston Reefers if you are ever in town. M. <Thank you for this follow-up, detailing your intended plan. Bob Fenner>
Re: Help with Acro Eating Flatworms.   11/5/06
Bob, Here is an update on my Betadine treatment http://www.bostonreefers.org/forums/showthread.php?t=33256 Here is the RC thread on the topic: http://reefcentral.com/forums/showthread.php?threadid=899108&goto=newpost Feel free to copy the text of my post to WWM. <Will do. Thank you Mauro. Bob Fenner>

Flatworm problem   7/22/06 Hi! Bob you have answered several questions, thank you.  Now here is a big one.  One of the local reef guys is downsizing from a 380 to a 180.  He has some amazing corals, but he has a flatworm problem.  I would like to buy several of his pieces because he is letting them go very cheaply due to the flatworms.  I did a much reading as I could (his was on of the longest threads on a forum ( http://reefcentral.com/forums/showthread.php?s=&threadid=756327 ) regarding their eradication.  Clearly, I don't see it working with a whole take problem; however, I was thinking about putting the corals I get from in in 2 QT tanks: one for the Acros (did them repeatedly over the course of a couple of months and then watch for signs) and tank for all other corals (starve the flatworms in that one).  My gut tells me this will work, what do you think? Vicki <I like your plan... careful siphoning might just do the trick here over a reasonable period of time. Bob Fenner>

Flatworms 6/22/06 Hello crew, I have a problem with pest flatworms in my refugium. This outbreak has been growing for about 6 months and for about the last 3 months I have increased the water flow to about 15x and have almost completely stopped feeding the refugium. I vacuum the pests off the glass and rocks every week when I do water changes but they just keep returning. <Typical> What can I do or get to keep the population down without wrecking havoc on my pods. <Not much besides manual removal.  Most times the population will eventually crash after a while.  Try using a turkey baster to blast them/debris off the rocks, sometimes helps.> Thanks for all the great help you provide. Sincerely Mark   <Chris>

Complaints Over Disappearing Flat-Worms, Can I interest You in Some Aiptasia or Cryptocaryon     5/4/06 Hello. <Hi John.> I have a 150 gallon reef tank. <Neat.> I had a problem awhile back with those pesty flat worms -- apparently I had a few hitchhikers on a piece of live rock that I purchased and we all know how fast they can reproduce.  Rather than try products like Flatworm Exit (which by the way does work) <Mmm…I wouldn't be so sure.> I was concerned that the toxic levels from the dead worms would eventually harm some of my favorite creatures.  So, I just siphoned out as many as I could while doing my weekly water changes.  This seemed to worked.  But I've been noticing over the past few months that the flat worms have been reproducing less and less.   In fact, if I look in the tank now I have to look hard to find just ONE where they used to be so plentiful.  Why is this?  Everything in the tank is extremely healthy and nothing seems to be stressed.  Where did they go????????   <Sounds like your diligent siphoning, disrupted their breeding and possibly any egg deposits did them in.> Do you know of this happening to anyone else? <Yes.>   Don't get me wrong - I'm not complaining - lol.  Yes, I do know for a fact that they were flatworms.  What happened to them? <See above.> John <Adam J.>

Single Flatworm or Advanced Scout??      5/4/06 Dear Mr. Fenner, <Jen S. here with you tonight.> Recently purchased a toadstool leather (Sarcophyton) from a reputable dealer that had it in his tank for a couple of months. I had been eyeing it for a while and finally, on a whim I might add, bought it. <Great one to have, enjoy it.> Brought it home, did not dip it and no quarantine (oops... my QT is currently cycling up for a pair of clowns) and anchored it tight with superglue. <Oops, QT is always the best course of action with adding to a tank.> And, of course, today I spotted a large 1/2 cm brown flatworm crawling across it. No others. I pulled it off with a pair of tweezers. I have a three month old 75 gal tank (no fish yet) with excellent water parameters that contains a Zoanthid frag and a Ricordea rock... both doing fine without any apparent flatworms. <Kudos for not adding fish yet.  As for the flatworm, I really wouldn't worry as of yet. It may have come with the new addition or it may have been there already.  However keep an eye on things anyway.> Question: Do I cut the leather free and do an Iodine dip now? Or do I wait to see if any more of these little guys arrive? I suspect it was in my tank already?? <I would just wait, no need to add more stress to the new addition.> Yet another "no QT tank" sob story for the record :-( <Yes, make sure that is up and running soon!  Good luck, Jen S.> Thanks, Russell in KY

Flatworm Infestation/Biological Controls - 05/02/06 Hello, <<Howdy!>> In my 40 gallon reef tank I have a large population of small orange things smaller than the size of a pencil eraser.  They are flat, have bilateral symmetry and no (or not noticeable) eyes, if that helps. <<Sounds like Acoel flatworms>> They reproduce very quickly as well. <<Under optimum conditions, yes>> They'll cover up half of a wall in the aquarium, I'll remove them and in two days it's covered again. <<Mmm, I usually consider these worms to be mostly an overrated pest to be controlled by limiting excess nutrients/detritus in your system...though when reproducing in plague proportions they can damage sessile invertebrates by shading/smothering>> Would something like a Blue Velvet Nudibranch or a Six Line Wrasse (both of which I'm told eat flatworms) help? <<The Nudibranch (Chelidonura varians) is the surer bet, but will starve to death once the flatworms are gone.  If you go this route perhaps you can loan/sell the flatworm to other like infested aquarists in your area...or make a deal to return it to the store to be utilized elsewhere.  If you decide to try a wrasse, though no sure thing either, I think one from the genus Halichoeres is a better pick than the Six Line>> All parameters are in check and salt is fine.  The other inhabitants are two clowns, a lawnmower blenny, a small tang (not big enough to go in the bigger tank yet.<<?!>>) several snails, two cleaner shrimp, random zoos, normal leather coral and Cabbage Leather Coral, Crocea clam, torch coral, red-tipped bulb anemone, and random mushrooms and feather dusters.  None of the inverts have been bothered/attacked by the orange worm things though. <<Typical>> Any help would be appreciated. <<Failing a biological control, manual extraction along with judicious feeding, detritus removal, and increased water flow/circulation can usually overcome this common pest>> Brian <<Regards, EricR>>

Flatworm Infestation/Biological Controls II - 05/03/06 Hello again, <<Hi Brian>> I did a Google image search for Acoel flatworms and it looks exactly like what I have.  I also noticed the Blue Velvet Nudibranch recommended so that's my plan. Thanks! Brian <<Do think beyond the flatworms and have a plan for the Nudi after they're gone.  Regards, EricR>>

Flatworm Predators/Controls - 04/18/06 I've been running my tank for about 4 months now with great success. <<Ok>> I have an 180gal. with two refugiums: the first is a 45 gal. Chaetomorpha refugium without sand, I also have a dark (blue light) live rock with 5" of sand.  Total system water with sump is around 300 gal.. <<Very good>> I'm writing to you because I seem to have a growing plague of what I believe are Planaria flatworms. <<Common/present in many folks systems...and a bit of an overrated pest in my opinion.  Harmless in most instances unless in plague proportions where they can completely cover corals, starving them of light/water circulation.  Reducing/removing dissolved organics with judicious feeding and aggressive skimming can usually control their numbers>> They are prevalent in the Alga refugium and now more and more in the main tank.  Some of the advice that I have gathered so far are: more circulation, manual extraction, and a natural predator such as the Velvet slug. <<The "slug" is a Nudibranch (Chelidonura varians).  They are reported to feed on Acoel flatworms, though I believe they are hard to find...and I've read there is a similar looking imposter that is often sold as the Velvet Nudibranch that DOES NOT eat flatworms>> My fish and Shrimp load is: Sailfin Tang, Lawnmower Blenny, Mandarin dragonet, Diamond Watchman Goby, Blue Tang, 2-peppermint shrimp, Coral Banded Shrimp, Blood red Fire Shrimp. I have a few corals and a clam also.  I'm interested in adding the velvet Slug for these worms or might you know of a natural predator in the Wrasses family? or others? What about the Six Line Wrasse or Carpenter's wrasse? <<None of the so called "flatworm predators" are completely reliable.  In my opinion the percentage is greater that they will completely ignore the worms.  But, I have had limited successes with wrasses of the genus Halichoeres...particularly Halichoeres chrysus.  You could give one of these a try, but I believe manual extraction and controlling water chemistry are your best bets>> Tanks a lot for the advice, Stephan Gaudreau. <<Hope you find it helpful.  Regards, EricR>>

Planaria In My Refugium - 03/22/06 Hi folks. <<Howdy>> I have a Chaetomorpha refugium, bare bottom with lots of pods and also lots of red/brown Planaria on the walls, detritus and within the algae. <<Sounds like my refugium about a year ago.>> Should I be concerned? <<I never was...these pest are overrated in my opinion.  Yes, they can become a "plague"...but are usually easily controlled with aggressive skimming, diligent feeding, etc..>> This refugium is fed unfiltered (no sock) raw water and then overflow into the sump and then pumped back to the tank. <<As it should be.>> I have not vacuumed this refugium in fear of taking away the pods. <<Understood and agreed...>> Is Planaria a dangerous thing in a refugium. <<Not in my opinion.>> My main tank (180) has  few but I am worried that they can be harmful to my corals. <<There's some concern if they reproduce to the point they drape/shade the corals...but this is usually a result of lazy/sloppy husbandry.  Aside from the other control methods mentioned, you can siphon them from the display when performing water changes.>> What do these critters thrive on? <<Neglect...but (more) seriously, an excess of organic material.>> Should I vacuum and add a filter sock to the fuge, limit nutrients? <<Mmm, no...defeats the purpose of the 'fuge.>> I realize that in getting rid of Planaria there will be collateral damage and I should expect population of pod to grow back up. <<Using chemicals/poisons is not the answer in my opinion.>> The tank has been running for about three months. <<Opinions/methods vary...please have a look here and among the indices in blue:  http://www.wetwebmedia.com/flatworms.htm  >> Thank for the immense help you have shared for the past three years. <<A collaborative effort...I'm thrilled to do my small part!  Regards, EricR>>

Flatworms On Hammer Coral - 03/21/06 I just recently received a small hammer coral from a fellow reefer.  The whole thing including the plug would fit inside of golf ball.  It's very small. <<Indeed>> I just noticed some small brown flatworms on it today.  I didn't know what they were until I tried to pick them off with a pair or tweezers.  The problem I'm having is that the flatworms are on the tentacles and every time I try to pick them off the tentacles retract.  I can't siphon them off or I'll damage the coral.  I want to get them early before they infest my tank. <<Likely too late, they have probably already spread.  Quarantine could have prevented this.>> What can I do?  I really need your guy's help, I can't think of anything.  Thanks in advance for all your help. <<You can try giving this coral a temperature and pH adjusted freshwater dip, though be aware this process is not without peril (do a search on our site re for more information...you can start here: http://www.wetwebmedia.com/dips_baths.htm).  Regards, EricR>>

Red/Rust-brown "Planaria" [Acoel flatworms] 10/28/03 I have all these little brown flat leach looking things on my mushrooms, frogspawn, hammer coral, crystal coral. I am wondering what they are and what to do about them. they seem to be hurting my stuff. please help... <you have the nuisance Acoel flatworms Convolutriloba or Waminoa. Much has been writ on our site and abroad about these organisms (check the sections in my Book of Coral Propagation or "Reef Invertebrates" book (with Fenner) if handy. Use the names provided here to do keyword searched of our archives on wetwebmedia.com   And please be sure to use a proper quarantine tank for a full 4 weeks in the future with all new entries (fish, coral, algae, sand, rock... everything) to prevent contamination like this form happening. You lucked out this time without QT... next time could be something devastating. Best of luck, Anthony>

Red/Rust-brown "Planaria" [Acoel flatworms] Redux 10/28/03 Hey there!  My name is Jas, I currently have a 55 gallon marine reef tank.  I have had it for 4 years now.  I have had fairly good luck with everything until just recently.  I bought a mushroom rock that came with more than I bargained for.  My tank is now over run with some sort of flat, beige, I don't know what to call them.  They are a little smaller than the size of a pencil eraser.   <you have the nuisance Acoel flatworms Convolutriloba or Waminoa> I've asked where I buy my fish and corals but they have no idea either.   <Ughhh... not a good sign that they could not ID this common creature. Please do inform them of our website as a source to free information to better their business, knowledge and success with customers> My mushrooms (where they started) have retracted, they have also spread to my frog spawn, crystal coral, and now they are also retracting.  Will they eventually kill everything in my tank?   <they are a plague/nuisance> Is there anything that could help naturally by eating these pests?  Please help me identify these critters.   <we answer this question often here at WWM. I am cutting and pasting my response below to the same question asked by another aquarist mere minutes ago... Much has been writ on our site and abroad about these organisms (check the sections in my Book of Coral Propagation or "Reef Invertebrates" book (with Fenner) if handy. Use the names provided here to do keyword searched of our archives on wetwebmedia.com.   And please be sure to use a proper quarantine tank for a full 4 weeks in the future with all new entries (fish, coral, algae, sand, rock... everything) to prevent contamination like this form happening. You lucked out this time without QT... next time could be something devastating. Best of luck, Anthony>

Convolutriloba retrogemma flatworms 10/15/03 Hi Crew! Hope your guys and gals are having as much fun as these critters - <more fun than you when you hear what they are at least <G>> they are having a ball in my 2.5 month old 75 gal Reef system. If you could put a name on them I would appreciate it. <they are the pest Acoel flatworms known as Convolutriloba retrogemma> I have looked and looked for an ID, but to no avail. <do also search under the name "rust/red-brown Planaria". Much in our archives on this critter and its eradication> Maybe it is the quality of the photo's...attached is mob scene that may help! Thanks for any help and keep up the amazing work. Fly 'em High! <they have symbiotic algae, grow fast in high nutrient systems (do consider if you have 10-20X water flow and a very efficient skimmer) and do not eat but rather irritate coral and benthic reef invertebrates. Best of luck, Anthony>

Convolutriloba retrogemma flatworms 10/16/03 Thanks for the quick ID response Anthony. I just read the section on pests in your book and it hit the nail on the head! <very welcome... and no worries, these worms generally wax and wane in aquaria with little or no harm done. They really do hate strong water flow, and in concert with aggressive skimming, they can be easily reduced> As usual this is a self made problem. I have disconnected the display tank from the refugium, which I am moving to the basement along with the sump and all support equipment. I will supply the display via 4 SCWD's feed by a Dolphin 5600 from the sump. The sump has a circulation pump and support equipment used to  condition water from the display via a 55 gal refugium. I hope once the turnover is increased and the supply adequately monitored and massaged, those pesky little creatures will cease and desist. By the way - congratulations on the excellent books and I am anxiously waiting for the next round! <Ahhh... thanks again! I am very eager to see the next volume in print too :) Kind regards, Anthony>

Fighting Flatworms Hello Bob & Co., <Scott F. at your service> I am currently stocking a new 350 gallon reef tank with new inhabitants and pc.s from my current 135 gallon reef. The problem is that my 135 gallon reef is infested with the little red flat worms. <Uh-Oh...> So far I have dipped the live rock over night in a diluted saline solution about 1.010 which seems to do the trick. The red worms fall right off and die immediately. By the morning the rocks are clean with some heavy collateral damage as far as bristle worms, feather dusters, etc; but the purple coralline algae remains intact. This is acceptable to me but now comes the live rock with SPS' attached to them, and also pc.s that have softies and LPS's attached. I know these will not survive over night. How many minutes do you think they can survive in this diluted saline solution? <Well, SPS do not, categorically, take well to full-strength freshwater dips, so I'd be very careful with hyposalinity treatment as well. If you are going to experiment with this, please try a small captive-propagated frag, and use a dip time of 5-10 minutes at the most. Study the coral carefully for a few days after the dip procedure. My conservative solution would be to engage in a rather tedious manual extraction through siphoning the animals out. Additionally, you can place the afflicted specimens in a quarantine tank with very high water flow...These little pests don't seem to do well in high-flow environments. Other "natural" controls would be the use of Mandarins and Macropharyngodon wrasses. Please note, however, that these fishes require substantial populations of amphipods and other fauna to thrive- they are not easy fish to keep by any stretch, so think twice before attempting to keep one for the sole purpose of flatworm control...Other people swear by Chelidonura Nudibranchs as another "biological" control...> How many minutes does it take for the rock to saturate itself so that the worms hidden within the rock will die too? <Hard to say- trial and error will determine that...Carefully experiment, as mentioned above.> What is the best procedure to rid the rock of the flatworms while not killing the coral itself? Some damage to me is acceptable but I cannot have those flatworms in the new tank. <See above for my other thoughts...Other ideas are to maintain impeccable water quality through skimming and other nutrient export processes, which will discourage the growth of these nasty guys...Best of luck! Regards, Scott F>

A Gathering of Platyhelminths Hey there crew- I was just wandering your website because my wife and I would like to get a salt water tank.  I'm a big fan of invert life especially the marine flatworms/Polyclads so much color and variety.  In my wanderings of your pages I've found ways to get rid of certain nuisance flatworms but my question is just the opposite.  Do you have any advice on how I should go about obtaining the larger, more exotic delicate beings? Or is it a crap-shoot of getting them from live rocks and coral type things? Thanx- Jackson <Mmm, much more of the latter. Flatworms are anomalies in a few ways... one is that they're hard as all get out to get rid of... and yet they don't ship worth a darn... often "just dissolving" enroute. I suggest hanging around specialized (reef) fish stores, joining a local marine club, staying in contact with marine wholesalers, etailers for their occasional "recruits"... that just "show up" on/with other organisms. Good luck. Bob Fenner>

Nudibranch or Flatworm     Hi crew! <Howdy Aryeh>     Last night I was shocked discover in my 200 g reef what looked like a black Nudibranch gliding along the sand and rocks.  It was about 1.5 - 2" long and it sort of looked like a dog (two ears or antennas in the front and a little tail sticking up at the back).  At first I was excited (I already have lettuce Nudibranchs) until I looked in the Reef Invertebrates and saw the picture of the Pseudoceros sapphrinus. <Looks like that to me too>   It looked very much like that except it didn't have the blue ring around it.  Here's a picture attached (it's the best I could get).  So is it a Nudibranch or a flatworm? <The latter> If it's the latter, how concerned do I have to be? <Mmm, not much... I suspect your tank is large (several tens of gallons in volume) and well-filtered... Should it die, dissolve, likely no problem. I would just enjoy it for now> I've already panicked a few times (for instance, when I first saw the lettuce Nudibranch or a big Bristleworm), only to discover they were harmless.  This thing is kind of neat and I think I could tolerate minimum damage to the corals.  But will it grow to plague proportions? <Not likely. I think you have a good mind, attitude toward/re such transients. At least a point of view I share... Bob Fenner>

Funny creature... Flatworm eating copepods 9/1/03 Crew. I have had two of these little things making rounds on my glass.. its fun to watch them.. they almost look like some sort of jelly fish, appears they maybe are feeding on diatoms? <actually a flatworm/Planaria feeding on copepods... quite harmless> I was wondering if you might be able to help me identify it? They shrink and expand their bodies to move around. I don't think it would cause any trouble, but any information is appreciated. Thanks! See image here: http://www.johnslife.com/images/squidly.jpg   Thanks again! John <they wax and wane with the copepod population. Anthony>

Flatworms What fish or any type of reef animal eats flatworms? Is there an easy way to get rid of flatworms? <All your questions can be answered by reading the following on our webpage: http://www.wetwebmedia.com/flatworms.htm http://www.wetwebmedia.com/pestflatwrmanthony.htm http://www.wetwebmedia.com/flatwormfaqs.htm> Thanks <You are welcome. -Steven Pro>

Worms/Planarians FW Tank - 8/22/03 I HAVE NEVER SEEN THIS BEFORE. I am quite flabbergasted as to what this might be. Hope you can help. <no worries... 'tis common> We helped a friend set up a (tank that was a salt water tank with a sump and all the essentials for a good saltwater tank) now a freshwater tank. There is only a perch, suckerfish, and a small catfish in an 80 gallon tank. A month later the tank has these small white teeny tiny worms that are every where. <they are common in new aquaria and with new aquarists. These worms/planarians are an unmistakable sign of overfeeding or excess food. Such matters are mitigated by messy feeding fishes, large gravel (traps detritus) and inadequate water flow (10X per hour is nice here)> Copper does not seem to be working, they look like they are multiplying right before my eyes. What is this and what is the cure. Checked the web sight and the disease books. No answer. These worms are not attached to the fish. <correct... they are harmless and non-pathogenic. They go away when the food source does. The tank needs some good gravel siphoning water changes> Multitudes of them are in the gravel and the rest trying to take over what space is left. Tanya   HELP <your friend needs a good beginners handbook and lesson on feeding and water changes... then they will be on a better track. Best regards, Anthony>

Flatworm ID - Harmless Here - 8/13/03 Hi Crew! You guys & gals sure deliver the goods! <thanks kindly <G> I wonder if someone can tell me what this is and what I should do with them (hundreds of them!). They are crawling out of my 4 week old live LS. <your critter is a flatworm/AKA Planaria... and is actually of the harmless variety. This creature preys on copepods and is common to flare in young tanks when the copepod population is strong (yay!) before the tank is overstocked (booo...) or stocked too quickly (too common). They will wane when the copepods do. No worries. Best regards Anthony>


Convolutriloba, the "red planarian" Hello:  I am interested in studying the biology of the flatworm species Convolutriloba, the so-called "red planarian" pest of many tropical marine aquaria.  We are studying the reproductive biology of these worms and are seeking sources of material.  Do you know of an effective means or listserver  that I can place a "call for help" to marine aquarists?  Thank you very much.  Will <Will, check out your local library for Ruppert and Barnes' "Invertebrate Zoology" and Jan Pechenik's "Biology of the Invertebrates", This should give you a strong start and my point you to other reference material that will fulfill your needs> <best, Chris>

Convolutriloba, the "red planarian" Pt. II Dear Chris: Actually my needs relate to obtaining specimens. <oops, sorry about that> I have all of the literature on this genus, but am in need of animals.  I've tried the local pet stores, but none have this pest in their tanks.  Is there a vehicle that I could use to contact marine aquarists?  Thanks,  Will J. <there are several online reef/marine aquaria bulletin boards I can think of that you could use, some examples are (but not limited to) reefs.org, thereeftank.com, reefcentral.com  Best, Chris>

What are these things?? More planarians, but freshwater? Good evening crew. <Good evening, Susan!  Sabrina here> I sent the following message Saturday but haven't seen any answer as of yet….soooo  I thought I might try again. Know you all are busy but any help you can give me would be much appreciated. <I'm so sorry I wasn't able to get back to you last night; I've been battling an illness in my wild angels and totally stressing about it, so I've been quite preoccupied.... many apologies> Since I sent the request I have been doing as much research as I can. I'm now about 99% certain these guys are planarians and I know they are supposed to be "harmless" but I also understand they will eat eggs. <What I know/can find, planarians really are harmless, and I've never heard/read about them eating eggs, but I'm certainly not positive about it.  Can you describe the worms?  You mentioned in your original message that they were white, flat, wider towards the middle, and about 3/4 of an inch long.  The size alone is suggesting to me that they may not be planarians, which (from my understanding) are typically 10mm or smaller.  Do they have a "V" shaped head?  That's pretty much a dead giveaway that they are, in fact, planarians.> I would really like to get rid of the planarians before breeding my fish. <I can certainly understand!> Also, I inadvertently spread the problem to my 30-gallon community tank by "seeding" the smaller tank with mature filter media from my big tank. <Oh, ugh....> This happened before I knew there was a problem in my 125G. I also forgot to mention that we are on well water if it makes a difference. <Mm, possibly, but I wouldn't think so.  Worm infestations can happen in tanks that use the best of water.  Usually, huge amounts of worms are the result of overfeeding, or otherwise excessive nutrients, and most often seen in predator tanks, like yours (several large predatory cichlids, an electric catfish, and an ever-messy Plec, in a 125 gallon tank, yes?).  Try cutting back extensively on feeding for a while and see how that affects the worm population.  Also, keep up with hefty gravel vacuuming to see if you can pull some of the little suckers outta there.> I treat any new water (with Prime) before adding to the tanks. Even though we test our well….you just never know. I have talked to the three LFS I patronize and two advised Copper... NO WAY was I going to put this in my tanks. <Ugh!  No....  Avoid this desperately!  Especially with your scaleless Plec and catfish.  Bad LFS, bad!  Deserves a swat on the nose!> One finally suggested a fluke eliminator. But he was a little hesitant and unsure so I haven't done anything except vacuum and perform water changes in both tanks and cut the food by ?. <Ah, yes, perfect.  Keep it up for a couple weeks, and see what happens with the wormies.  Also, I'd like to mention that I had the occasional planarian showing up in my plant tank (well, lots of 'em, really), and they seem to have been eliminated by a very minute amount of Fenbendazole (proprietary name Panacur) that I used to rid my tank of (shudder) hydra.  I certainly haven't seen a single planarian (or hydra!) in a month or two.  But then again, my planarians were about 2-3mm long.  Tiny.  The Fenbendazole did not affect my bacteria bed in the slightest, nor did it have any effects on any plants, shrimps, or fish.  It is usually sold as a goat-worming medicine, but can even be used as a wormer for discus.> My water parameters have not changed and all the fish are fine. I still have all 14 new Platy babies and they are growing like crazy. And I still have a gazillion "creatures" that give me the creeps. <Well, keep up with what you're doing, for the time being, and see if the worms start to die out.  I'd also like to mention our chat forum http://wetwebfotos.com/talk/  as we have rather recently had another fellow with a similar problem - perhaps you guys can compare notes.> Thanks in advance for any assistance you can provide. <Glad to help, and again, sorry for the late response!>

Planarians - Part 2 Good evening Sabrina <Hello again, Susan!> Thanks for responding so quickly! I do hope you are successful with your angels. My research of turbellarian flatworms (freshwater planarians) indicates they can be up to 1 inch in length. I was able to capture one of these little buggers and compared it to pictures found at www.planarians.org and it looks like the picture. Yes... they have a V shaped head (upside down V ). <Yeah....  "V" shaped heads almost always mean planarian, IME.> For now I am going on the assumption they are planarians and I am trying to obtain some Panacur. However, I am a little uncertain about the dosage. Somewhere on the Internet I read that the dose for hydra is 0.5 grams per 100 liters. What dosage did you use? <Honestly, I used so little, I don't know the actual dose.  Likely less than a gram in my 72 gallon tank (filled to ~60 gallons).  It took a couple of days to wipe out the hydra completely, and I'm really not sure about whether it nailed my little planarians or not, but I used to see 'em frequently, and since treatment have seen none.> Assuming that I treat both tanks this will work out to about 3 grams of Panacur. Also, do you think I can safely use this in the tank with the Platy fry? <Possibly, but if you can, perhaps wait a couple weeks for the fry to grow up a bit, if you can, just to be on the safe side.> I worked on the large tank some more today...moving rocks, vacuuming, cleaning the pump lines and changing the water. Didn't see as many critters today, so maybe I am getting them under control. <Hope so!  Sounds like you're doing a good job of reducing their chances of getting a meal, so they may very well die out on their own.  Give it some time, and keep doing as you're doing, especially if you think you're seeing results already.> Thank you again for your help.  Susan <Glad to be of service!  -Sabrina>

Hammering flatworms 07/25/03 <Hi Karen, PF with you today> I have a 250 gal. reef that's been up & running for about 3-4 months, and is now thriving.  I placed a fairly large hammer coral in it about 2-3 weeks ago & it is doing extremely well; however, I've noticed some flat, flesh-colored organisms measuring 1/8" in length that are randomly scattered & can move quite quickly along the length of the tentacles of the coral.  I don't see these "creatures" on any other coral in my tank & I've never seen these before... do you know what they could be & if they are parasitic or symbiotic in nature? Any info would be helpful, Thank you, Karen <Well Karen, it sounds to me like flatworms. Check here: http://www.wetwebmedia.com/flatworms.htm for more. If these are what I suspect they are, keep a close eye on them. Sometimes they can be harmless, other times, they reach plague proportions and do damage by shear numbers. Let us know, PF>

Levamisole for Acoel flatworms I recently found an article on the web, that Levamisole will help eliminate Acoel flatworms. The article actually used the name Concurat L.  Do you know of anyone that has used Levamisole to eradicate these pests?   Thanks, Eric <I do not recall anyone specifically... but it is not too surprising. Levamisole is a popular de-worming remedy for animals at large. Use only with caution... test on specimens in a bare QT first. Anthony>

- Malachite Green for Flatworms - What is the correct way to prepare Malachite Green powder for dosing into a reef system to eliminate flatworms? <Zero, nada, nothing... I would not recommend this treatment AT ALL! Malachite green will kill the invertebrate life and miscellaneous fauna in your reef tank even at low doses, and certainly at a dose high enough to kill a flatworm. The proscribed path of action would require the removal of the inverts, live rock, etc and so you would also remove the flatworms and get them back again as soon as you put this stuff back in the main display.> What concentration should be used, how often, etc. <Again... don't do it, you will regret it. Please spend some time reading though this FAQ, it will provide some background: http://www.wetwebmedia.com/pestflatwrmanthony.htm Cheers, J -- >

Acoel flatworm eater, The New Book 5/30/03 Hey at WetWeb, <Howdy!> I spoke with Anthony a couple months back and ordered his and Bob Fenner's new book, and I'm curious as to when I will receive it.  I assume it will be soon??? <indeed, my friend. We just got word from the printer that they estimate a June 13th release. It then needs to be shipped to Cali (less than a week) and then Bob and I need to fly/meet together to sign the pre-orders. We'll get them out promptly!> Also, I was perusing your site and noted that when people asked about ways to eliminate Planaria from their systems, the Six-Lined Wrasse was not mentioned.  This is a fish that will wipe out a flatworm infestation in short order.   <unfortunately not all do to exclusion. Many aquarists have this popular fish but they will not control Acoel flatworms for them> Perhaps you'd like to include that info in future responses.  They are wonderful little fishes to boot! <agreed... will be sure to archive this response> Look forward to a response on the ETA of the new book. Thanks, Peggy Nelson <Thank you for sharing, my friend. with kind regards, Anthony>

Rust-Brown Acoel flatworms 5/20/03 Here is the best pic I could manage. These guys are maybe 1/8th inch long. I am wondering what they are and if they are reef dangerous. If they are what will get rid of them? Anything eat these guys? Shane   <the Acoel flatworms you have, bud, are quite a nuisance and a common problem. Also know as red/rust/brown "Planaria". One of the genera represented includes Convolutriloba. Please use the common and scientific names proffered here to do a keyword Google.com search of our archives (many FAQs on this topic) and beyond on the Internet. kind regards, Anthony>

Natural Flatworm Eradication Technique....Maybe Bob, et al., <Hi Chuck PF here this AM, not sure if I qualify as an et or an al> My 300 gallon tank was filled with these ugly buggers...until I added a refugium with low flow rate. ALL of the flatworms have since migrated to the refugium...not a single one in the main tank. Perhaps this is a clue as to how to get rid of them ? The display tank has been flatworm free for almost 1.5 years, and the refugium is loaded with them. <Wow! Very cool.>  I really do not care that they are in the refugium since some sources I have read suggest that they could actually be beneficial to the overall health of the system, albeit their unsightly appearance. Maybe I stumbled across a technique that could be used to eradicate these pests ? <Sounds that way to me.> This is how it should work: 1. Either set up a permanent low-flow refugium OR set up a temporary low flow tank that is plumbed into your system. 2. Increase the flow rate and/or water motion in your main tank with powerheads, closed loop pumps etc. 3. Then wait..... 4. Watch all of these buggers migrate to the low flow tank. 5. Once you got em in the temporary tank, disconnect it and flush em or just leave them alone in the case of a permanent low flow refugium. Do you think my situation is just a fluke, or something really exciting that I stumbled on? <See below> If someone could duplicate this, maybe we could confirm this technique, n'est pas ? <Sounds like a plan to me, if multiple users repeat your results successfully, then you may well be up for Saltwater Sainthood. :) > Best Regards, Chuck <Thanks for sharing Chuck, hopefully your technique will work for others. Have a good one, PF>

New Flatworm Treatment?   4/27/03 Heard there was a new item on the market that safely treats flatworms in a reef tank - please advise. <Well.. I did a Google search using the terms "treats flatworms" and "flatworm treatments".  I found a few products that may work.  I was talking to Ananda and she will look for it at this weekend's International Marine Aquarium Conference in Chicago.  So we will keep our eyes open.  Also check out WWM's Flatworm page here:  http://www.wetwebmedia.com/flatworms.htm   Hope this helps!  Phil>

Flat worm eradication - 4/9/03 Thank you very much for the quick response. <Thank you> I have had a look at the links in your note, great information though it does seem to be a little contradictory at times. <likely to cover all aspects> One question, I posted the same plea for help at reefs.org and received a response from Delbeek indicating that as a last resort I might try a drug called Levamisole. Have you ever heard of anyone using this drug successfully? <I personally have never heard of this drug. I want to make a statement right here and now, that I do not believe that these animals are at all harmful. Overall, I too, have gone through various incursions of these little worms. I still have a few here and there, but for the most part, there are very few. I used no drugs and did nothing but what I am expected to do as a Conscientious Marine Aquarist. I did water changes, had proper circulation, (based on what is located on this site) and blew them off and siphoned them up. Over time they minimized with no impact to any of my animals (corals et al) Again, I have seen little evidence of these animals decimating tanks and killing off inhabitants. I believe there is no need to panic. No need for medication, no need to add a new animals that may or may not eat them only to suffer other issues in the tank, just give it time with proper water chemistry and I think you will be happy with the results.> At this point I am going to siphon off as many as I can, do more frequent water changes (weekly 10 to 15%) and see what happens over the next couple of months ...... and keep my fingers crossed. <Beautiful solution and cheers to you for having this attitude. So many people affect their tank adversely by adding chemicals or other animals to their tank that could be potentially more trouble than the Planaria. The old adage the "cure is deadlier than the disease" comes to mind. I like your solution. Good on ya'. Paulo> Cheers

Planaria (flatworm infestation) - 4/8/03 I have a problem with out of control flatworms (pictures attached). <Great pictures!> Any ideas on how I can control them would be appreciated. <See here: http://www.wetwebmedia.com/flatworms.htm and here: http://www.wetwebmedia.com/pestflatwrmanthony.htm also please follow the links to the FAQs as well. The tank is a 90 gallon reef I setup in November, with 130 lbs of live rock and a sand bed of 2 to 4 inches. I have a 30 gallon sump in which I run a red sea skimmer and UV sterilizer( UV off for last month or so). Lighting consists of two 175W HM (6500K) and two 40 watt NO fluorescents. The water parameters are good, nitrite and ammonia are 0 and nitrate is less than 10 ppm. Temp is between 80 and 82F, SG is 1.025. <Nothing ringing out as to why you may have a problem. Hopefully you will have some luck in the many FAQs and articles here that I linked above. Good luck, Paul> tks/Ken

Possible solution to Brown flatworms Thanks for your reply on my Calcium reactor problem. Here is something I have posted a few sites, maybe this will help you or someone else. About 6 months ago, I had a huge problem with brown flatworms. They were all over, and nothing I did seemed to have much of an impact. I tried every type of Nudibranch, which always disappeared after a few days. I tried increasing water flow, they just moved. I tried sucking them out, they multiplied faster than I could remove them. I bought 6-line wrasses, 8-line wrasses, every type of crab, Hawkfish, blue Chromis, you name I tried it. After talking with many fish stores about there problems with flat worms, I tried a new approach that WORKED! I don't know if one of these would have worked by itself, but I did all three. It took SEVERAL months for them to disappear, but I do not see any signs whatsoever. 1) lower the water temperature to about 76 degrees( the flatworm multiply very very fast at high temperatures) 2) raise ph to 8.3 and do your best to keep it there. I used a product named "reef buffer" from Seachem. I'm sure anything that keep ph at 8.3 would work 3) maintain alk at high levels. I also used reef builder, again, just keep alk high. It took about 2-3 weeks to begin to notice that the population was decreasing. I continued to Vacuum as many as I could each week when changing the water, and I have not seen any for several months. I hope this help someone Zander Gray <<Thanks for sharing. Cheers, J -- >>

So-called "Planaria" [flatworms] Hi I have been reading from your website and I am trying to figure out if what I have in my tank is Planaria. I have a 65 gallon tank with live rock, 1 clown, 2 sleeper gobies, 1 coral beauty, 1 powder brown tang, 3 damsels, and a puffer. The tank has been up and thriving for 7 months. What I have on the bottom of my tank and on the powerhead, thermometer and rock are white. They appear to have a tail? Not very noticeable and have not overrun any rock or glass, but I am wondering what they could be. <we cannot say from the general description and without a clear photo, but rest assured that there is a common flatworm in aquaria that is white. Often present when its food is abundant: tiny copepods (white dots). Do look over: http://www.tcnj.edu/~maughme2/faq.htm and here: http://www.rshimek.com/ Best regards, Anthony>

Flatworms Hello Bob, <Anthony Calfo in your service> I have a question concerning flatworms. And the more I read the more confused I get. <hmmm...do read this piece of mine (http://www.wetwebmedia.com/pestflatwrmanthony.htm) and the many FAQs on the subject ( http://www.wetwebmedia.com/flatwormfaqs.htm)> First off I have set up a twenty gallon tank in the office where I work. Have 1 scarlet hermit and 4 snails. Added a false Perc clown, who now has developed a fuzzy growth on his left gill. I believe this to be Lymphocystis.  <yes. may very well be. There are not many "fuzzies" in marine fishes...true fungus being very uncommon and Lympho being rather common...look here as well: http://www.wetwebmedia.com/lymphfaqs.htm> The clown is very active and does not show signs of distress. I now know from your site that this is not as bad as I first thought. And will eventually clear up. <agreed> Now on to the flatworm problem. I have two kinds of flatworms. Please correct me if I am wrong. One is a white kind that actually looks like a tooth, I have read that these eat copepods and such. And will not get to plague proportions.  <yep... and rather a good sign that you have a healthy copepod population to sustain them> I also have green to greenish brown with a orange or reddish spot in-between the forked end. These seem to be all over everything. I was considering getting a fish to help control this problem. Can you recommend one? I was looking towards a six lined wrasse, as they stay small and are hardy, and colorful. Will this work.  <yes.. a good change and such small wrasses are some of the most effective and hardiest choices> Or how about a scooter blenny?  <not recommending any dragonets/blennies as a first choice... not hardy or effective enough> I am not to concerned about the pod population, as I know it may be decimated by the wrasse,  <not so much...> but I was told the scooter blenny, well actually mandarin, would eat the flatworms and some algae but not harm the pods as much. <that is very incorrect... pods are most all/only what they eat... the reason why they are so difficult in aquaria that have difficulty sustaining copepods populations for years in continuum> Thanks in advance Paul <best regards, Anthony>

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