Polyclad worm killing my snails?

[Makara23]

I rarely look at my tank late into the night, but saw this guy at 4am. Based on the sticky and googling THIS, I think it's a Polyclad flatworm. The pattern seems a little big though, so I'm not sure. My snails slowly disappear and I've been blaming my hermit crabs for it, but now I'm not so sure if it's the hermits or this worm that's been killing my snails.

It came on my live rocks 6 months ago, and this is the first time I've seen it. Please help me ID it, and how I can try to catch it next time.

 

[vetteguy53081]

I rarely look at my tank late into the night, but saw this guy at 4am. Based on the sticky and googling THIS, I think it's a Polyclad flatworm. The pattern seems a little big though, so I'm not sure. My snails slowly disappear and I've been blaming my hermit crabs for it, but now I'm not so sure if it's the hermits or this worm that's been killing my snails.

It came on my live rocks 6 months ago, and this is the first time I've seen it. Please help me ID it, and how I can try to catch it next time.

View attachment 3105747
View attachment 3105749

Can’t open video but larger polyclads can. Siphon with a 1/4” tubing and discard
Look daily for next two weeks for any presence of eggs which are tiny

 

[Second Shot]

I can’t see the videos but I had one that was eating snails. Are you finding the snail shells with a bunch of slime on them? Once I finally got the polyclad out the snail deaths stopped.

 

[Cell]

Looks like it. Hopefully you can find it again and remove it.

 

[Makara23]

Can’t open video but larger polyclads can. Siphon with a 1/4” tubing and discard
Look daily for next two weeks for any presence of eggs which are tiny

I can’t see the videos but I had one that was eating snails. Are you finding the snail shells with a bunch of slime on them? Once I finally got the polyclad out the snail deaths stopped.

Hmmm sometimes this forum has problems displaying videos. But here are screenshots of the video. Is this a polyclad worm?

If I dipped the rocks in Coral Rx, I'm assuming this will probably get rid of it?

 

[cpschult]

Hmmm sometimes this forum has problems displaying videos. But here are screenshots of the video. Is this a polyclad worm?

If I dipped the rocks in Coral Rx, I'm assuming this will probably get rid of it?

View attachment 3106277View attachment 3106280

Better off with prazipro. I'm not sure if coralrx will kill it. I found one when I tore down my 125 gallon tank. They are pretty dam tough.

 

[vetteguy53081]

Hmmm sometimes this forum has problems displaying videos. But here are screenshots of the video. Is this a polyclad worm?

If I dipped the rocks in Coral Rx, I'm assuming this will probably get rid of it?

View attachment 3106277View attachment 3106280

Yep - looks like one

 

[Makara23]

Better off with prazipro. I'm not sure if coralrx will kill it. I found one when I tore down my 125 gallon tank. They are pretty dam tough.

I will consider this if I can't catch it in the next month or two. The problem with prazi is that it might inadvertently kill the good stuff too. I have tons of small feather dusters on all the rocks.

 

[Mhamilton0911]

Definitely a polyclad flatworm. Not a fun friend. I went through this a while ago. Tough to get rid of because they can squeeze into the tiniest nook in any rock. If you see it hide in a rock if you can take the rock out is your best bet. I found they will hide and die inside a rock if you dip, but they try to evacuate when the rock is left out of water. This was my best chance of getting mine out. I threw out the rock that I couldn't confirm if it died or not, it just never came out. The next rock I let it sit out and it came out in it's own. I also tried siphoning out but they tear easy and can still get away partially. Overall I found 3 and removed, and have spotted one since, but my tank blew up in population of the tiny collinitsa snails so I'm sure it's being well fed and not showing itself. I've had no other obvious snail deaths.

 

[Second Shot]

If I were you I would remove any snails left and then it will have to go out hunting. I stopped adding snails and then it had to come out and search. Siphon it out because it will fall apart very easily if you try to grab it.

 

[TnFishwater98]

QT the rock in a smaller tank until you catch it.

 

[cpschult]

I will consider this if I can't catch it in the next month or two. The problem with prazi is that it might inadvertently kill the good stuff too. I have tons of small feather dusters on all the rocks.

Do not prazi the tank, if you have a lot of polyclads they can poison your tank when they die

 

[ccole]

That definitely looks like a polyclad. If you remove your snails, you may have some luck creating a trap out of an old water bottle and using a clam as bait (the ones from the grocery store).

I had two hitch hike into my tank from some live rock and caught them when they were prowling the sand bed with a net (I checked very late at night, around 1am).

Good luck!