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FAQs about Flatworm Identification 3

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

Related FAQs: Flatworm Identification, Flatworm ID 2, Flatworm ID 4, Flatworm ID 5, Flatworm ID 6, & FAQs on: Flatworms/Planaria 1, Flatworms 2Flatworms 3Flatworm Behavior, Flatworm Compatibility, Flatworm Control, Predator Control, Chemical Control, Flatworm Selection, Flatworm Systems, Flatworm Feeding, Flatworm Disease, Flatworm Reproduction, & Worms, FAQs: Worm Diversity FAQs, FAQs 2, FAQs 3, & Worm IDs 1, Worm IDs 2, Worm IDs 3, Worm IDs 4, Worm IDs 5, Worm IDs 6, Worm IDs 7, Worm IDs 8, & Worm ID FAQs by Group/Phylum: Flatworm Identification ID, Nemertean, Proboscis, Ribbon Worm ID, Nematode, Roundworm ID, Nematomorpha, Horsehair Worm ID, Acanthocephalans, Thorny-headed Worm ID, Polychaete Identification, Polychaete ID 2, Tubeworm ID, Hirudineans, Leech ID, Echiuran Worm ID, Invertebrate Identification

Euphyllia Eating Flatworm? Polyclad -- 4/30/09
<Hi there, Cath!>
I've lost several of my Euphyllia corals in the last couple of months.
This morning, I've found what I think is a kind of flatworm on many of my frog, torch and ancora pieces. With a close look and more attention, I saw that all my Euphyllia are literally infested by this 'little' (some are up to ½') beast.
There are also a lot of yellow eggs around them. Here is, in a joined piece, a picture of the beast. The shot was not taken by me, but by a fellow reefer of my area who has the same problem. What exactly is this flatworm?
<Looks like a Polyclad of some sort to me (see link below for more info).>
Is there a way to get rid of them?
<Manual/diligent removal of all visible worms/eggs. In addition, check any and all other corals (and rockwork if possible) for further evidence and remove any you come across. I'd also put the corals, one at a time, in small tub or container with tank water, and using something like a turkey baster, blast any areas of dead skeleton/rockwork with water to hopefully dislodge any unseen juveniles.>
I've made a lot of searches and haven't found anything about it.
<That's understandable. I looked everywhere and only found a couple of unconfirmed hobbyist reports related to Euphyllids and suspected Polyclad predation. Furthermore, I was unable to find any documentation, anywhere, confirming actual predation of any coral species by these worms at all. That's not to say that it's not possible however. Apparently, there's a lot of information still needing to be discovered/revealed regarding these large worms. The general consensus is that they're all predatory - consuming various colonial or sessile organisms such as Tunicates, Bryozoans, bivalves, barnacles, etc, as well as other small invertebrates such as amphipods, small snails, Polychaete worms, and even other flatworms. Also, some evidently feed on algae, especially diatoms, but only as juveniles. The problem with this situation is that unless you've actually seen the worms eating live coral tissue, you have to consider that their presence may be secondary/incidental. Perhaps the corals are dying due to one or several other reasons -- for instance environmental issues (water chemistry, chemical warfare/allelopathy, etc), or due to fish/crabs, etc picking at them. The culprit could even be another type of flatworm (perhaps Acoels?) or something else entirely. The Polyclad flatworms could be there to prey on the real predator(s), or other incidental/harmless amphipods, etc, that have congregated to feast on the sudden bloom of algae and/or dying coral tissue. Admittedly, an infestation level of anything near a damaged coral doesn't look good, but I'd rule out other possibilities just to be sure. I have to admit, if I were in your shoes, I'd likely err on the side of caution and remove as many Polyclads as I could. Had there been just one or two, I'd have left it/them, but in the case of many -- bye bye!
I've got some links for you to read through. Here's a similar situation: FAQ titled 'Euphyllia Health issues / hitch hiker ID... likely allelopathy, env. 6/9/08', at this link: http://www.wetwebmedia.com/carydisf7.htm
Allelopathy issues: http://wetwebmedia.com/cnidcomppt3.htm
Flatworms: http://www.wetwebmedia.com/flatworms.htm >
Thank you!
<You're very welcome! Take care, LynnZ>

Halimeda seeds? 4-13-09
I am a long time reader and I truly appreciate the site. I have two identifications questions for you. The first is a golf ball sized seed pod looking thing that came attached to a clump of Halimeda, I have searched
plenty but found nothing about Halimeda seeds or anything of the seed ball.
<Mmm, no... Halimeda is a Thallophyte (an algae)... reproduce by spores... true plants (Embryophytes) have seeds>
I have now noticed little green maybe Nudibranchs on the tanks glass near the seed ball. I just want to check the IDs to be sure I am not unleashing a plague in my tank. I know I should of probably not put something in my tank with out knowing what it exactly what it is but the store didn't think it was a big deal.
Thanks for the help,
Ryan King
Current Tank setup:
AGE - three months
55 Gallon with 17 lbs live rock and 60 lbs lace.
Lighting is a 65x4 power compact.
30 Gallon sump with about 20 gallons of water in it.
The tank runs at 78F and salinity of 1.024
I used instant ocean salt mix and RO/DI water.
Current stock:
Fish: Yellow Tang and two Ocellaris Clowns
Shrimp: Cleaner, pair of Peppermint
Stars: Blue Star, Brittle Star
Snails: 20 various small cleaners
Crabs: 10 Red Leg hermits, 10 Blue Leg hermits
Coral: Xenia, GSP, Mushroom, and a few misc frags
<Looks to me to be a colonial Ascidian... the clear bunch is dead... Bob Fenner>

Correction to today's dailies - 4/13/09
Hiya Bob!
So I was looking at that ID question that came and talked to Lynn about it this morning. It is definitely not a colonial Ascidian.
Lynn found these photos:
We think it is a snail egg mass, likely that of a tulip snail, which likely wouldn't be good news for Ryan's tank to have such carnivorous snails.
And the other image which he thought were Nudibranchs look to be Acoel flatworms, specifically Convolutriloba, similar to the photo here:
Which came from this site:
and the differences can be seen here:
Lynn found all these images. She's really great at getting these ID's!
<Thanks much... Will amend on the morrow... a shame that I've deleted the original senders email address. BobF>
He wrote back!!!! YAY!!!!! Lynn replied to him. M
<Ahh, very good. B

Re: Halimeda seeds? Egg Capsules and Acoel Flatworms - 4/13/09
<Hi Ryan, Lynn here this evening. I sure am glad you wrote back. My fellow crew member, Mich, and I put our heads together this morning and came up with some information regarding the two mystery items in your tank. The follow-up will be posted tomorrow at the dailies, but I've included a copy here as well (see below). The only thing I'd like to add is that we've got lots of information at WWM regarding Convolutriloba flatworms and Tulip snails in marine systems. Just enter the terms in our search engine and you should be good to go: http://www.wetwebmedia.com/WWMAdminSubWebIndex/question_page.htm .>
Thanks for the info - I guess it shows that I am clearly an electrical engineer and not a biologist (algae has no seeds... doh).
<Heeheeee! No worries. I hate to think of the wholesale Godzilla destruction I could cause if I even stepped a toe into the world of electrical engineering!>
I do enjoy the site and your book.
<On behalf of Bob and the rest of the crew, I thank you!>
Best Regards,
Ryan King
<Take care, LynnZ>

Little rust red things, Planaria, 4/6/09
I have these little rust red colored flat worm looking things on my glass and now on my live rock.
Any idea what they are and how to get rid of them?
<Most likely Red Planaria, see here
http://www.wetwebmedia.com/pestflatwrmanthony.htm and related FAQs for more.>
They are about 1/8" wide and slightly longer than wide
Please see attached picture.
<Tough to tell for sure from that picture.>


Mysterious Creature: Likely Flatworm  11/17/08 Hello Crew, <Hello Susan, Lynn here today.> I have had a 180 gallon reef type aquarium for about three years now. <Very nice.> One of my favorite activities is to explore the marine-scape at night with a flashlight and magnifying glass. <You're mind kind of people!> It's amazing what turns up sometimes, <Yes, indeed.> which brings me to my question. Last night I found a new mysterious creature and my searches of WWM and Google have turned up nothing as to its identity. So maybe you might have an idea what it was. Unfortunately I don't have a photo, but I'll do my best to describe it. <Okay> The creature was affixed to the glass at the back, just above some rocks. It was somewhat circular in shape and flat -- it looked a lot like a large amoeba, about 3" in diameter. It was light brown in color and opaque. There was no discernible head, although there was a white spot, like a large grain of sand, that remained stationary relative to the movement of the animal. The creature moved with a slow, circular motion, its shape changing fluidly as it moved. Lightly frilled edges and occasional bubbled-up patches formed underneath as it moved. <It might be some kind of flatworm, but I'd need a photo to confirm.> I was so curious that I turned on the fluorescent lights. It reacted to the light and got somewhat smaller, moving slowly into a more elongated shape (about 1" x 2"). A darker area seemed to appear down the midline as it slowly shimmied down the glass. It continued to grow smaller and more elongated so that it was almost a sausage shape by the time it reached the sand. Then it disappeared behind the rocks. <Terrific observations. Yep, it sounds like a Polyclad flatworm, of which there are many, many species. They're able to change shape just as you described and are quite interesting to watch. I'd love to see a photo of this little guy but I can sure understand why you weren't able to get one. Hehee, they never seem to understand �Stay right there while I grab my camera!�. For more information on Polyclad flatworms, please see the following link: http://www.wetwebmedia.com/flatworms.htm > Anyway I am baffled and really curious about the identity of this odd creature. Perhaps the Crew has seen something like this . . . <Yes, we do get inquiries related to flatworms from time to time, as can be seen in our FAQ�s starting here (be sure to go through the associated links at the top of the page as well): http://www.wetwebmedia.com/fltwmid.htm > Thanks for your help. <You're very welcome. It's always a pleasure to converse with a fellow enthusiast. Let's face it, there aren't that many of us that sit up at night with a flashlight, peering into our tanks! By the way, a flashlight with a red lens is terrific for observing nocturnal animals and their behavior. The beam from a regular flashlight is usually enough to send most critters diving for cover! Also, if you have a magnifying glass, definitely get it out and take a look-see. That opens up even more possibilities.> Susan P.S. I love your web site. It's been a major source of information and advice since I started this fabulous hobby and has kept me from making a lot of mistakes. <Heehee! Me too! Bob has certainly amassed an impressive amount of material that continues to grow with each incoming query. Thank you sharing your observations with us! Take care, Lynn>

Worm or what?   10/1/08 This thing is huge (silver dollar size), and I think it's moving relatively fast. It looks to me like a giant flat worm. <To me as well. Perhaps a Pseudoceros sp.> I guess it can't reproduce and I guess it might be the reason I have not had luck with shrimp in this tank and my serpent stars are being eaten slowly. <Mmm, doubtful it is this Platyhelminth...> That's a whole lot of guessing so maybe I'll just attach a picture and see what the experts think. Thanks, As always love this site, Jesse <Read here: http://wetwebmedia.com/flatworms.htm the linked files above. Bob Fenner>

Planaria or other SW "bug"? ...Planaria  9/11/08 Hi WWD team, <WWD?> Hope all is well on your end of this email. <Yes, thank you.> I have been through many of your ID and FAQ pages and haven't found anything that seemed to fit my scenario. I have a 75g future reef setup that has been up and running for four months. I have around 50-60 lbs of base rock seeded with 20 lbs of live rock a SSB of around 2-3" aragonite that was dry (no live sand here! Waste of money IMHO). <Will become live with time.> No coral or fish yet since I wanted to give the tank a few months to mature nicely. <Good idea.> I have a cleanup crew of two emerald crabs, <Not to be trusted.> five Nassarius snails, <Good.> five Trochus snails, <Good.> three Margarita snails <These snails can live over a hundred years in their natural environment which is significantly cooler than most reef systems. These snails typically die a slow death from being cooked in the too warm home aquarium.> and 10 blue leg hermits. <Again not to be trusted.> Over the last two months, I have noticed some peculiar white/off white "bugs" on the glass that some have considered flatworms (I am assuming Planaria) but nothing definitive. <Yes, they are Planaria.> They are small, maybe 1 mm at the most and crawl around on the glass. I have also seen a few move more like an inchworm. I do have plenty of amphipods I see scurrying around the live rock at night and had seen small white bugs early on that were round with white legs branching out all around (isopods or copepods?) <Could be either.> that I think many people describe as the "tiny white spiders on my glass" but this seem to be replaced with these little buggers. I finally snapped a decent photo of them and was hoping to see if you can ID. Here is a link to the suspects in question: http://s400.photobucket.com/albums/pp87/bbl_nk/?action=view&current=bugs 1.jpg <These are Planaria. More on them here: http://www.wetwebmedia.com/flatworms.htm http://www.wetwebmedia.com/pestflatwrmanthony.htm You can see similar images here: http://www.wetwebmedia.com/flatwrmfaq2.htm > Thanks! <Welcome!>

Flat worm? 03/24/2008 First thank you for the service that you provide. <<Thanks for the comments. Andrew here today>> I have searched the site for similar flat worms as well as other sites and I cant really make up my mind what to do about these guys. I have a CPR hang on refugium with built in protein skimmer. I saw three of these guys when looking at the fuge from the side today. I pulled one out with tweezers to try to get a picture which I am not very good at anyway. Sorry about the quality. They seem light brown when out of the tank and slightly reddish when under the light. I have only seen these in my fuge on my macro algae. I have not seen them anywhere in the display. I have a six line wrasse perhaps he / she eats them? They are only a few millimeters in length and have a uniform border, no jagged edges. <<Planaria flatworms. They thrive better in lower flow areas of the tank, which is probably why your noticing them in your fuge. If they are not in plague proportions, then you can leave them alone, or simply such them out when you see one with a turkey baster>> The flow in the CPR is very low as there is only the inlet pump (RIO) for circulation and protein skimming. I have a ton of flow in the main tank as it is sps dominated hence my concern. Any info would be greatly appreciated. Here is the best I could do picture wise. http://i250.photobucket.com/albums/gg252/mlgiii23/worm.jpg <<Thanks for the questions and the nice photo, hope this helps. A Nixon>>

Strange Creature... Planaria... Mmmm, flatworms   3/9/08 Hey Gang. <Hi Wuf, Mich here.> I have been trying to identify this creature for a few days. I can't for the life of me figure out what it is. They are starting to accumulate on some of my rocks. To give you an idea of scale, the specimen pictured in IDme1.jpg is right at 1/16th of an inch. Any idea? -wuf <Well the good news... Yes I can tell you what it is... The bad news... you don't want it. Is a pest, an Acoel flat worm. Yours is looking like its reaching plague proportions. You will likely need to address the situation. More here: http://www.wetwebmedia.com/flatworms.htm http://www.wetwebmedia.com/pestflatwrmanthony.htm Sorry to be the bearer of bad news, Mich>

Re: Strange Creature... Planaria... Mmmmm Flatworms 3/10/08 I guess the good news is now I know what the problem is, so now I can attack it. Figure a few taps of a hammer to the bottom glass should take care of them all (j/k). <Heehee! I feel your pain! Happy siphoning.> Thanks for your time, Mich. <Happy to help! Sorry it wasn't better news for you. Mich> -w

Worm ID please   3/3/08 Hi! <Cath> Here is a picture of ''the thing''.(joined piece) A reefer of my area see it on is hammerhead. I guess it's a kind of flatworm but I'm not sure...if so, is it a bad one? Regards. Cath <Are some sort of flatworm... Not likely harmful. Please read here: http://wetwebmedia.com/flatworms.htm Bob Fenner>

Some Kind of Flatworm... Planaria... Likely Convolutriloba retrogemma 12/03/2007 Hi my name is Mike <Hi Mike, my name is Michelle, my father shared your name.> and have a 150 gal reef tank and have some kind of flat worm. <Yup... > and I'm not sure if that's what they are. <Is Planaria, a flatworm, likely Convolutriloba retrogemma> I need to know what these little things are cause they are eating all of my star polyps and some of my mushrooms. <They generally flatworms tend to cause injury by smothering the coral'¦ and once the corals begin to decay the flatworms start to consume the Zooxanthellae. Your corals do not seem to be covered to the point that I would expect death'¦ perhaps there is something else at play here. More here and the related links in blue: http://www.wetwebmedia.com/pestflatwrmanthony.htm http://www.wetwebmedia.com/flatworms.htm
Good luck,

Flatworm ID -- 09/29/07 Hello crew, <Hi there, Mich here> I'm a big fan of all of you. <Me too! There are some fantastic people here!> My husband jokes around with me that while most people emulate movie stars and baseball players, my heroes are all scientists. <What's wrong with that?> I've asked around some forums, but no one is quite sure what to make of this. These grayish-blue colored flatworms are very small, larger than a copepod, smaller than a "normal" flatworm. It's been suggested that they are blue due to something they've eaten. <Maybe, maybe not.> They have the two horns at the end. <The end if you will.> The "head" or front part is either segmented or has a darker blue line behind it at the "neck." Some of the larger ones *may* have little ruffles around the sides. I was looking at them with a magnifying glass. I only see them on my red slime algae, <They are likely elsewhere as well, just may be harder to see in other places.> which I just had a bad outbreak of. <No fun!> None of my corals are suffering, <A good sign.> and I don't see any of these flatworms on any corals. <Lucky!> Is it possible for flatworms to eat red slime? <I guess anything is possible, they generally feed on detritus and algae.> They seem to have shown up around the same time as the red slime, <Maybe just the first time you noticed them because of the background color of the Cyanobacteria.> and have exploded in population the past few days. <Yikes!> The larger ones have beautiful patterns on their backs, like a diamond back snake or an x-ray, I can't tell on the small ones. It really seems too good to be true--beautiful Cyano eating flatworms. <Yes I do believe you are correct here.> By the way, my tank temperature is 70* F maintained by chiller, <Really 70 F? Is this a typo or are you really running a cool water system?> if that makes any difference. <I know naught on cool water systems.> These are the best out of about 50 pictures I took. <Oh yes, been there done that!> I asked for a microscope for Christmas. <Heehee! Will you ask Santa to deliver on to me as well?> Thank you for any help you can give me. <Not too much I'm afraid. They do look like flat worms and I would be very careful as they are known to reach plague proportions. Though some aquarists report having a continual population of Planaria that never gets out of control. If it were my system I would try to remove as many as possible as quickly as possible. Good luck to you,

Flatworms: Amphiscolops sp...what to do? - 8/19/07 I found these in my tank. Can you please guide me on what to do, if anything at all? <No worries and no need for action (nice picture, though!). These are harmless little flatworms (Amphiscolops sp.). They tend to pop up in tanks and disappear a short while later. Please see these links for more info re: http://www.wetwebmedia.com/flatworms.htm http://www.wetwebmedia.com/flatwrmfaq3.htm <Take care --Lynn>

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