Can you help ID

[FragLife]

Hi

These cone shape shells stuck to a coral or rock.
It appears to be small crabs, that are afraid of the light, that live in the shell.
Thanks ...a feather duster I bought was stuck to this.

 

[ginpang]

Barnacles!?


Sent from my iPad using Tapatalk

 

[Betta132]

Those are barnacles. They're filter-feeders that should be fine in your aquarium if it's reasonably large.