Worm id

[JonsNano]

Finally after many years I think I have found my snail killer, pics are crap but I think it maybe some type of Medusa worm, going to take the rock out soon and likely break it to get the worm out, it stays here always thankfully lol

 

[JonsNano]

For reference I have very roughly circled the mouth and some of the ?stingy things? on its head lol I know there are many many types of worm and fall into similar groupings so a rough id would be great

 

[ISpeakForTheSeas]

Finally after many years I think I have found my snail killer, pics are crap but I think it maybe some type of Medusa worm, going to take the rock out soon and likely break it to get the worm out, it stays here always thankfully lol

The term Medusa worm applies to a few different critters (see my quote below), but none of them would be snail killers - they'd all be harmless/beneficial detritus feeders.

The quote below may help us figure out which kind you have, though, especially if you can describe the tentacles (the "stingy things" you mentioned) a bit:

Yeah Medusa Worm is a term generally used to refer to specific kinds of Apodid (taxonomic order Apodida) sea cucumbers (though the term is also applied to Loimia medusa, a type of Spaghetti Worm, and is sometimes generalized to mean any kind of Spaghetti Worm - spaghetti worms are from the taxonomic family Terebellidae).

OP, does your worm move around the tank, or does it live in a tube? It looks like it has some oral tentacles in a couple of those photos - can you get a clearer picture of them or could you describe them? (For example, are they thin, spaghetti like tentacles? Are they thick all the way from one end to the other? Are they thick at the base and tapered to be thin at the tip? Are they feathery/do the tentacles have "branches" coming off of them?) Would you describe your worm as transparent (totally see-through), translucent (kind of see-through), or opaque (not at all see-through)? If it lives in a tube, would you describe its tube as transparent, translucent, or opaque?

 

[JonsNano]

The term Medusa worm applies to a few different critters (see my quote below), but none of them would be snail killers - they'd all be harmless/beneficial detritus feeders.

The quote below may help us figure out which kind you have, though, especially if you can describe the tentacles (the "stingy things" you mentioned) a bit:

Thanks for the reply, this thing is a definite snail killer maybe not medusa worm but the rock had a pile of snail shells by its(the worms) hideout.
I was going to say tentacles but thought it may be the wrong terminology also lol
If it lives in a tube I cannot see the tube, it defo has oral tentacles which I’m sure are thicker at the base and tapered with a possible small ball on the end hard to tell as they are almost transparent, they don’t have branches that I can see, the worms body that I have only seen a maximum of an inch of is not translucent it’s creamy coloured with striping from memory the stripes didn’t seem like legs just colouring.
I will take pictures when I remove this beast but going to see if any weirdos want it at the lfs before trying to remove.
Thanks for the help

 

[JonsNano]

I would also say that I counted at least 6 tentacles

 

[JonsNano]

The term Medusa worm applies to a few different critters (see my quote below), but none of them would be snail killers - they'd all be harmless/beneficial detritus feeders.

The quote below may help us figure out which kind you have, though, especially if you can describe the tentacles (the "stingy things" you mentioned) a bit:

Ok I managed to nab another picture annoyingly I was a bit late grabbing the iPad as it had completed introversion by the time I took the pic, I shone a bright light on it for a while and as it went into introversion (the perfect time to catch all its tentacles in all their glory) I went to grab my iPad . It’s body looks semi translucent with white stripes going down from where it’s tentacles hit the mandible looking things.
Im thinking this might be related to or a cucumber.
I look forward to your thoughts and others thoughts!
Thanks

 

[ISpeakForTheSeas]

Ok I managed to nab another picture annoyingly I was a bit late grabbing the iPad as it had completed introversion by the time I took the pic, I shone a bright light on it for a while and as it went into introversion (the perfect time to catch all its tentacles in all their glory) I went to grab my iPad . It’s body looks semi translucent with white stripes going down from where it’s tentacles hit the mandible looking things.
Im thinking this might be related to or a cucumber.
I look forward to your thoughts and others thoughts!
Thanks

Yeah, I'm thinking it's a cucumber - I know some Leptosynapta spp. (for example) can look like this; I'd expect it to have tiny, stubby branches coming off a ways down the tentacles.

Regardless, a sea cucumber wouldn't be killing your snails, so I'd guess something else (possibly something living nearby) is killing the snails, or that the sea cucumber is scavenging the already dead snails (but even that seems unlikely to me).

 

[JonsNano]

Yeah, I'm thinking it's a cucumber - I know some Leptosynapta spp. (for example) can look like this; I'd expect it to have tiny, stubby branches coming off a ways down the tentacles.

Regardless, a sea cucumber wouldn't be killing your snails, so I'd guess something else (possibly something living nearby) is killing the snails, or that the sea cucumber is scavenging the already dead snails (but even that seems unlikely to me).

I honestly can’t see any stubby branches coming off of the 7 tentacles or any branches at all for that matter, the tentacles do extend a fairway I would say around 2 inches and do seem to have a ball on the end.
I know there are around 1000 species of sea cucumber and I definitely have not been able to see pictures of all of them, but what I have noticed in the pictures I have seen, that not one has a mouth like my beasty lol
Other than it being some nightmare bobbit Medusa hybrid unknown worm, maybe the snail deaths could of been down to it releasing toxins as they disturbed it ‍, I even noticed one of my hermits was killed or consumed there in its cave (I swear lol) possibly as it ate some toxic dead snail I dont know just spit balling now lol I would love to id it though or see something similar.

I have had the rocks for almost ten years and found most hidden things when I moved house and also when I had to downsize due to unfortunate circumstances, so I am doubtful of any other nasty creatures in my tank but who knows and the countless stomatella,dove,bumblebee and other snail shells in its exact area tell me it is likely the problem, but I may be surprised when I pull the rock
Thanks for your reply

 

[ISpeakForTheSeas]

I honestly can’t see any stubby branches coming off of the 7 tentacles or any branches at all for that matter, the tentacles do extend a fairway I would say around 2 inches and do seem to have a ball on the end.
I know there are around 1000 species of sea cucumber and I definitely have not been able to see pictures of all of them, but what I have noticed in the pictures I have seen, that not one has a mouth like my beasty lol
Other than it being some nightmare bobbit Medusa hybrid unknown worm, maybe the snail deaths could of been down to it releasing toxins as they disturbed it ‍, I even noticed one of my hermits was killed or consumed there in its cave (I swear lol) possibly as it ate some toxic dead snail I dont know just spit balling now lol I would love to id it though or see something similar.

I have had the rocks for almost ten years and found most hidden things when I moved house and also when I had to downsize due to unfortunate circumstances, so I am doubtful of any other nasty creatures in my tank but who knows and the countless stomatella,dove,bumblebee and other snail shells in its exact area tell me it is likely the problem, but I may be surprised when I pull the rock
Thanks for your reply

You're right that the mouth is quite unique - it's been bothering since you pointed it, because I'm confident that I've seen one just like it before (probably in the past ~12-18 months), but I can't remember where or even what kind of creature it was on.

If it is a sea cucumber, then it wouldn't be releasing toxins that kill the inverts (sea cucumber toxins are ichthyotoxins - they primarily harm fish; inverts have a pretty high tolerance for them).

Yeah, when you pull the rock, if you can get pics of the full length of the critter and /or clearer pics of it, I'd be interested to see.

 

[JonsNano]

@ISpeakForTheSeas my cuce had been looking rather skinny the last few days so I decided today to whip it out lol sorry for the bad pics and since removal it has got skinnier and looks unhappy, any idea of what type it maybe?


you can’t really tell in the pic but it’s body has orange lines running the length of it, and I’m happy my lfs is going to have it in a sump so will live for longer hopefully.

 

[ISpeakForTheSeas]

@ISpeakForTheSeas my cuce had been looking rather skinny the last few days so I decided today to whip it out lol sorry for the bad pics and since removal it has got skinnier and looks unhappy, any idea of what type it maybe?


you can’t really tell in the pic but it’s body has orange lines running the length of it, and I’m happy my lfs is going to have it in a sump so will live for longer hopefully.

It's definitely an Apodid (taxonomic order Apodida) cuke of some variety; I'm not entirely sure which kind, and I'm not sure at this point how to narrow the list down - sorry. There's a surprisingly large number of translucent Apodids (both with and without orange lines that would be visible in pics).

That said, looking at some of the species in the three families, some of them have tentacles that don't branch, and others have tentacles with a ton of tiny branches that basically make the tentacles look like feathers (these tiny branches would be very hard to see on a translucent specimen like yours), so either of those could explain the odd tentacles.