Are planaria dangerous for fish?

[mdfa.ca]

Yesterday I tore down a small tank that has been causing me difficulties (healthy looking fish dying for no apparent reason) and discovered something interesting on the bottom, in the detritus. Little squiggly worms, about 1/16" to 2/16" in length. I scooped some up and put them under microscope hoping to identify them. Pretty sure they are planaria, a type of flatworm. . They are supposed to be mainly parasitic. Are these critters dangerous to fish? Could they be the cause of the fish problems?

[Dandee]

Here is some information I found on them.

http://www.aquarticles.com/articles/management/Ali_Planaria_Worms.html

http://www.fishdeals.com/fish_diseases/planaria_white_worms/

[mdfa.ca]

Thank you, Dandee, that makes me feel better, though it would seem I've been feeding my fish too much...

[CACAdmin]

I found it interesting that the first article mentioned that some catfish and snails will eat them. I have had planaria a couple of times and then the 'magically' disappeared. Maybe my snails and BN's helped clean them up. :Dunno:

[Melody]

Planaria aren't necessarily dangerous, but the conditions surrounding an infestation can be. It means there has been lots of overfeeding going on. This isn't difficult to do when we have to overfeed for pet snails, baby pleco's, etc. They also particularly like vegies, it seems, so I'm guessing rotting plants would make them happy too. When I see them, I cut back on the feeding. Disgusting creatures :Eeewww: .

[Pamelajo]

I have had them a couple of times, guppies like to eat them. I usually do a few really good gravel vacs and they disappear. I have heard that they will dry snails crazy getting up under the shell.

[Melody]

Yes indeed, I've seen that one first hand! I even treated snails for them once and watched them slither out from under the shells before they died. I used Prazipro and dipped the snails as I didn't want to treat their tank for too long in case it irritated them.

[mdfa.ca]

Yeah, I took a note of overfeeding. Luckily it was my quarantine tank so not a big deal. Probably because fish weren't always hungry in there but I still fed. But I gotta pay attention to make sure I don't do that with the other tanks.

P.S. Actually they're kinda neat to watch under the microscope but I can imagine, if you were a snail and had one under your shell, it would probably feel like ants crawling under your skin.... (sssshhhiver!!!)

[Pamelajo]

it would probably feel like ants crawling under your skin.... (sssshhhiver!!!)
:eek:

[GaryofMontreal]

I find them kind of interesting, but while they are harmless, the conditions that allow them to flourish are dangerous for fish. They're an indicator of trouble in a tank, and often the very conditions that they love will leave you with the kinds of fish deaths you described. They like water that's polluted.
I've had them a few (or more) times when filters blocked up, when I slacked on water changes or when I overfed.

[Melody]

I think suffering plants will also contribute, because I've obtained plants before and the Planaria shows up shortly thereafter. I'm sure the fact that plants can trap food doesn't help either.

I'm horrible for overfeeding and it's tough to feed the bottom without doing so, just in case. Bare tanks were real eye openers for me. I first started using them with Guppies and continue to be amazed at just how much food hits the bottom. If it weren't for snails, I'd have a mess more often than not.