Medusa worms

Zirco

Member
A few months back I bought some Chaeto that turned out to have two medusa worms in it. I tossed it as soon as I saw them but now I'm finding medusa worms in my display tank. So far I've pulled out 4 including a tiny free-floating one. Luckily they're pretty easy to suck out of the rockwork with a turkey baster when I find them. The biggest so far has been about 1/4 inch in diameter and maybe 2 inches long. You can see it here:

https://www.youtube.com/watch?v=RNhNnYPTRW0

I had heard that they are hard to keep alive in a tank so I'm surprised that they seem to be propagating. How worried should I be? I know they can emit a toxin that can wipe out a tank if they die or get stressed but so far my fish seem OK even though I've definitely damaged some of the worms before I was able to fully remove them. Perhaps because they're so small they aren't emitting enough toxin to be a problem?
 
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That's weird, they shouldn't be breeding in a tank. They only use the medusa nuke if they are very injured or get sucked into a powerhead. You could sell them if you cath them.
 
A few months back I bought some Chaeto that turned out to have two medusa worms in it. I tossed it as soon as I saw them but now I'm finding medusa worms in my display tank. So far I've pulled out 4 including a tiny free-floating one. Luckily they're pretty easy to suck out of the rockwork with a turkey baster when I find them. The biggest so far has been about 1/4 inch in diameter and maybe 2 inches long. You can see it here:

https://www.youtube.com/watch?v=RNhNnYPTRW0

I had heard that they are hard to keep alive in a tank so I'm surprised that they seem to be propagating. How worried should I be? I know they can emit a toxin that can wipe out a tank if they die or get stressed but so far my fish seem OK even though I've definitely damaged some of the worms before I was able to fully remove them. Perhaps because they're so small they aren't emitting enough toxin to be a problem?

That's a filter feeder, a rock dwelling sea cucumber. Completely harmless. They find a spot they like in the rock work and just hang out and feed on any passing nutrients. Dosing the tank with phytoplankton will help them thrive.
 
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