Help with ID snails and tiny circles on rocks

[Mac01]

Hi - newbie here.

Can anyone pls help confirm if these are baby nassarius snails as I suddenly have a lot of them and I've read it's not likely to reproduce in reef tank (1 looks black/white, the other brownish). I do have 3 large nassarius snails in my 1.5 year tank.

Also, please help ID small circles on my rocks. I have a few of these and I'm thinking it may be vermetid snails or feather duster, and if so do I remove? When I blow water against it it retracts to nothing (into the rocks) - the last pic shows the circle right under the frag plug, the other right in the middle.

Thanks

 

[Gumbies R Us]

@ISpeakForTheSeas

 

[Mac01]

@ISpeakForTheSeas

No. Where do you put the tags? Thanks

 

[ISpeakForTheSeas]

No. Where do you put the tags? Thanks

They tagged me with the "@" before my username.

Can anyone pls help confirm if these are baby nassarius snails as I suddenly have a lot of them and I've read it's not likely to reproduce in reef tank (1 looks black/white, the other brownish). I do have 3 large nassarius snails in my 1.5 year tank.

The black/brown snails with white spots/stripes are Lightning Dove Snails, Pictocolumbella ocellata, and dove snails are known to reproduce in our tanks - these snails are good CUC (so they're friendly).

Also, please help ID small circles on my rocks. I have a few of these and I'm thinking it may be vermetid snails or feather duster, and if so do I remove? When I blow water against it it retracts to nothing (into the rocks) - the last pic shows the circle right under the frag plug, the other right in the middle.

I can't say for sure from the pics (they're too blurry for me), but definitely not Vermetid snails.

Four possibilities:
-Feather duster worm (should have a crown that looks like a bunch of feathers - one big stalk down the middle and bunch of tiny branches off the stalk - extended outward from the center into a circle)

-Solitary tunicate (these have two holes; an in-siphon and an out-siphon - I can only see one hole in the pics)

-Filter-feeding sea cucumbers (similar to the feather dusters, but instead of these looking like they have feathers, it looks more like plant roots branching out from the center)

-Some kind of anemone (tentacles, most likely without any branching off of them, instead of feathers or roots).

Feather dusters would have a tube they live in that they retract into; tunicates, sea cucumbers, and anemones retract into a little blob/ball. Tunicates would ball up on the outside of the rock (they can't dig/purposefully move into crevices), but cucumbers and anemones may be literally inside the rock.


In this case, the critters are most likely harmless, but there is some risk with cucumbers and anemones.