need help with id

[Manny]

I have never seen this in my tank untill tonight. I have no idea where it came from. please help....... it's blowing my mind

 

[nanoreefer22]

Is it like a snail or like a sponge?

 

[DevIouS]

Small cleaner clam:scratch:

 

[romain]

Clam?

 

[reefman]

clam, probabably not photosyntic. filter feeder. tiny ones r common, bigger ones usually die off in live rocks.

 

[Manny]

Thanks for the replies

I thought it was some kind of clam but, wasn't sure.
Are they good, bad, or just there?
Do they move around?

thanks in advance

 

[inkblue]

:party::wink1::birthday: i haVe simiLar oNes that were attacHed to a z00 roCk...

 

[DevIouS]

Just there.....
I had 2 that moved around. Now I don't see them anymore.:happysad:

 

[Aqua Pro Builder]

Looks like a clam.

They move when the environment is not favorable enough. When I tried to introduce an oyster into my tank, couple of these swimmed off the oyster rock to where the scallops are for couple of days. Finally, they lodged themselve in the middle of a sponge and don't wander around anymore.

Looks harmless to other animals in the tank.