What on earth is this thing living under my duncan? Pulled mysis in on a kind of web?

[MmeAssoc]

Does anyone know what this fleshy-looking spiral thing is, at the base of the duncan?

Sorry for the blues/poor quality. I can try to get a better picture tomorrow, if it helps.

I had thought it was a new head growing - it's been there since I bought the frag two and a half months ago. It's never moved from that spot, but it's slowly gotten bigger. It started as just a small bump, but has slowly turned into this spiral/circular mass.

Just now I fed the tank some frozen mysis shrimp, and I saw a small clump of the shrimp got stuck on an almost invisible 'webbing' strung between this part of the duncan and a rock about 10-15cm away.

As I watched, the 'webbing' seemed to be retracting towards the duncan, pulling the shrimp clump towards what I thought was the new growth. You can see in the photo the shrimp have been pulled right up to the 'mouth' of this thing (the shrimp are the white fuzzy bit at the top of the spiral growth). It ate the shrimp, and now I'm wondering what on earth sort of critter it is???

Any ideas? It hasn't ever moved from that spot, it's just slowly gotten bigger and rounder.

 

[MaxTremors]

It’s a vermetid snail. While not dangerous in and of itself, it’s little snot webs it sends out to catch food can irritate coral and cause issues over time. There are many ways to get rid of them (just search here), it’s best to get rid of them sooner rather than later as they will spread and constant irritation can cause a whole host of issues with corals. I usually don’t worry about the little ones (there are many species), but the larger ones pose more of a threat.

 

[MmeAssoc]

It’s a vermetid snail. While not dangerous in and of itself, it’s little snot webs it sends out to catch food can irritate coral and cause issues over time. There are many ways to get rid of them (just search here), it’s best to get rid of them sooner rather than later as they will spread and constant irritation can cause a whole host of issues with corals. I usually don’t worry about the little ones (there are many species), but the larger ones pose more of a threat.

Thank you! i had thought it could be a vermetid, because of the web, but all the pictures I could find online show vermetids being much smaller than this thing. It's good to have confirmation! I'll read up on removal.

 

[D4jack]

I would poke a needle through it in multiple places and scrape around inside the tube. It should kill it without harming the coral it is attached to.

 

[MaxTremors]

Thank you! i had thought it could be a vermetid, because of the web, but all the pictures I could find online show vermetids being much smaller than this thing. It's good to have confirmation! I'll read up on removal.

There are some massive species. Some are free standing and have these branching colonies that look almost like a branching stony coral. Gallery Aquatica had one that was nearly two feet tall.