Black shell with something sticking out of the opening

[slee]

Hi all,

I recently noticed a black spot with a hard exterior shell that seems to have something living in it. Theres thin antenna looking strands that stick out of it and moves back into the shell if something goes near it. Any ideas of what this could be? I couldn’t find anything online but maybe I wasn’t using the right search terms.

 

[cloak]

Vermetid snail. These aren't necessarily bad, but an abundance of them in a tank could lead to problems. The net that they cast out to capture food has been known to irritate corals.

 

[malacoda]

Vermetid snail.

Yep, vermetid.

 

[Just_Pete]

Get rid of it now. Can multiply like crazy. I’d scrape it off and siphon it out to avoid spread.

 

[Losthawk69]

Different species. the larger ones you don't want these small ones I had in many tanks never had an issue. The larger size species look like spiral sheep horn that kind you don't want. Just filter feeders I had them grow next to sps with no issues at all. Gel super glue the tops they say kills them but , you will be chasing your tail.

 

[slee]

Thank you all for the answers, if my monti cap grows over the top of this would that be equivalent to capping off the tops or would it kill the part of the monti thats covering it?

 

[Losthawk69]

I had them grow over the snail and the nail was still they no issue but if you only see one cut it off or use needle-nose pliers and get it from the base off to the trash can but where there is one there is more they start as small white snails moving around the tank find a spot they love and grow a feeding tube size of 1cm throw out their net to catch food in the water the only way not to get them it's to start a tank with dead Rock and quarantine everything before you put it into your main display

 

[slee]

I had them grow over the snail and the nail was still they no issue but if you only see one cut it off or use needle-nose pliers and get it from the base off to the trash can but where there is one there is more they start as small white snails moving around the tank find a spot they love and grow a feeding tube size of 1cm throw out their net to catch food in the water the only way not to get them it's to start a tank with dead Rock and quarantine everything before you put it into your main display

good to know, im going to start another tank in a few months so ill keep this in mind. thank you