View Full Version : Planaria/Flatworm question

01/28/2000, 08:26 PM
Please forgive me if I am going over old territory here, but I looked in the archived posting about this subject, and one thing is still unclear to me. Does anyone know if any kind of mandarin will eat the flatworms? I read in TRAv1 that the spotted/psychedelic mandarin:


will, but says nothing about the other kind:


I am partial to the way the other variety looks however, and am wondering if they will do a similar job at controlling the 'red hordes.' Thanks to all that respond.

01/29/2000, 07:08 AM
Have had the "other" in my tank for about a month and have seen no evidence that he is eating the flatworms in my tank. It is very dificult to be sure. He swims around constantly picking at something on the rock but cannot tell if it is the worms. There seems to be no reductions in the numbers but they multiply so fast. If I were to buy another would get the spotted. Please let me know, if you get one, how it does.
Have also tried a 6 line wrasse which doesn't seem to have helped. Am concentrating on siphoning at this point.

Larry M
01/29/2000, 07:37 AM
I have splendidus (your "other" pic) and he does not eat flatworms. In fact, from most accounts, neither do so on a regular basis. Also, there is the feeling among some (me too) that buying a fish which can be difficult to keep in the hope of eradicating a pest is not the best idea.
Flatworms can truly be a pain in the neck, I have one tank which has them. If you do a search here you will find some ideas about how to get rid of them, but for the most part syphoning probably works the best. You can get them to congregate in an area first to make it easier by shining a flashlight in one corner.
Good luck,

Larry M

See my tanks at Northern Reef (http://www.reefcentral.com/northernreef/index.htm)

01/29/2000, 07:45 AM
here one for you:
i have TONS of these pain-in-the-neck in my refugium, but NONE in my main tank! (at least none that i can see)
i also have the "other" type of mandarin. the other fish in the tank are: puple tang, tomato clown, sailfin blenny and bangaii cardinal. have serpent, brittle and lankia stars plus a tiger tail cuke and snail and hermits.
so, can i assume that the mandarin is eating these flatworms? :)

have a nice day

come and visit my reefs:
Reeftopia (http://www.geocities.com/psychocoralchopper/reeftopia_main.html)

01/29/2000, 09:19 AM
I was doing the siphoning thing, but it seems as though I have more the next day. I can't believe how fast these guys repopulate the tank. Whenever I do a water change, I am sure to siphon up a few hundred of them that are on the rocks, but many of them are on the substrate as well, and I don't want to siphon up too much of that.

I guess I was really hoping that a predator would be the answer. LarryM, mandarins are pretty difficult to keep, but in the past I have had very little trouble keeping them. My only complaint as far as mandarins were concerned was how effeciently they ate up all the copepods.

David Grigor
02/01/2000, 10:47 AM
I had a problem with flatworms everywhere. I have since then added a sixline wrasse and a yellow coris wrasse and problem solved.

I am not 100% which one if both are feeding on them.

I have heard from others that the sixline wrasse will keep in check. Other people have said that it doesn't touch them in there tanks.

One or the other of these wrasses solved my problem but not a 100% guarantee. Both wrasses are great fish and worth considering if you have the room in your tank. tank........

David Grigor
02/01/2000, 12:41 PM
My yellow coris is the same as you mentioned Goby. It it solid yellow with NO white belly.

As Goby mentioned both feed well on prepared foods and have been quite hardy.....

02/01/2000, 02:23 PM
HI Gang, Along these same lines, My Reef developed quite the Flatworm problem. Since I was moving soon I figured I would deal with it at that time ( which is now).
My question is this. I moved my reef, sand et al, I placed all of the sand into a 45 Gal. tank with no lights at all, will these little guys die W/O light? (I hope) or will they just lay dorment and wait until I put the sand back into the new 180 Reef :) to show their ugly little flat faces again. I'd just as soon buy all new L.S. rather then reintroduce them to the new reef. TIA for any help..David

02/01/2000, 02:52 PM
accidently cracked my 10g w/ the flatworm problem, so the entire tank was without light for 3-4 days. now that i have it all set up again, the flatworms are back with a vangence.
i would recommend to get new sand/ liverock... everything pretty much. these worms are evil: it's driving me nuts. i was so tempted to rinse all the liverock in freshwater, but figured that there will probably still a few that survives. then they'll reproduce and i'll have the problem again. is there any hope? maybe i'll try and find a yellow coris.

have a nice day

come and visit my reefs:
Reeftopia (http://www.geocities.com/psychocoralchopper/reeftopia_main.html)

02/01/2000, 09:00 PM
Although it may seem tempting to do a freshwater rinse, I have heard of people doing it, and having the flatworm problem resurface later that week. When the LFS here gets a sixline in, I'll be sure to give it a try despite their tendency to nip at the microfauna. I purchases a green mandarin a few days ago, and so far, I have not seen it eat a flatworm. Perhaps it will develop a taste for them. I hope anyways.

02/01/2000, 11:40 PM

I had a problem with them (red flatworms) in my jawfish setup. I "installed" a 6-line wrasse, and the worms shortly disapeared. I have not seen them since, and the 6-line has adapted to eating prepared foods ( was eating well in the LFS before purchase) as well as eating these pests, so no harm is being done to the "predator" in this case.

I also had a problem in my 125 when it was first setup (with a piece of rock from the jawfish setup) that soon began to get out of control. I added a 4-line wrasse and a yellow(refered to as a "golden" coris at FFE (does not have a white underbelly)) coris (mostly to ensure that my clam would stay pest free) and they as well have eradicated the flatworm population in my reef. I do not know which wrasse in this case is acting as the "predator" as they were both added at the same time.

Although several "experts" have reputed the claims that these fish will help with problems such as red flatworms, I see them as a definate possible solution that is not detrimental to the fish in question as they all take well to prepared foods and other microlife in a closed system. Some other advantages are that they are found in most LFS as they are very common, and they are relatively inexpensive (<$20.00)

While they do seem to work in some cases, many will say that they have not had success with such "predators" of the flatworms. It appears to be a case by case solution depending on the fish in question. Also, be aware that these types of fish can and will deplete the life of sandbeds and other microfauna. While they will not decimate them to the extent that the dragonets you have pictured, they will do some damage to these populations.

Thank you, drive thru.....


The quest ( and the questions) continues...
www.iag.net/~vigg (http://www.iag.net/~vigg)

The Actinic One
02/02/2000, 06:18 PM
Got the same problem, flat worms everywhere. Bought a mandarin (the "other" kind) and a six line about two weeks ago. Nothing. I started getting worried about the mandarin not eating and set up a brine shrimp hatchery - one day too late. He is now dead, the six line is eating prepared foods and the flat worms have not slowed. I have heard that a particular nudibranch will do the trick (c. varians). They are supposedly serious predators of flatworms but will probably die after the worm population crashes. I would be vbery interested to hear if anyone has a sure fire solution - if there be one ...


02/03/2000, 09:25 AM
This seems to be one of the thornier problems of unwanted animal abundances. I have seen the "other" kind of Mandarin work on these worms in a friend's tank. You could see the fish pick the worms off the rock. The fish eventually died from getting stung by an anemone and the flatworms bloomed. My friend got another Mandarin and the worms disappeared. There were also plenty of small bugs in the tank to support the fish - and perhaps "balance" its diet.

Judging from the reports here, it may well depend on the individual fish. Mandarins are notorious for low survival when purchased from LFS's as they are often maintained in tanks which lack sufficient foods, and the poor fish seem to get to a point that after a while even if put into a tank with sufficient food, they die. This may explain some of the lack of success with them.

Cheers, Ron

[This message has been edited by rshimek (edited 02-03-2000).]

02/12/2000, 08:08 AM
OK, here's an update on my planaria situation. I have not seen the mandarin eat a single flatworm. When I bought it, it was 'Ally McBeal' skinny, and now it is fat. I have noticed a decline in the flatworm population, but that isn't necessarily saying anything about the mandarin's eating habits. For some reason, some of my corals are looking ill, and two of my peppermint shrimp have died suddenly. I am thinking that some agent in the water is killing my inverts, and is thinning out the flatworm population. I digress. That post is a separate post.