Yellow sponge with siphon or vermitid?

[Ratsinmyhead]

Looks almost like a yellow vermitid snail but the base is not spiraled and they are not hard. Anyone have any idea on ID?

 

[WVNed]

Sponge

 

[vetteguy53081]

Its a tunicate and good filter feeder

 

[SteveMM62Reef]

Most likely that is a Tunicate, also called Sea Squirts. They are less demanding than Sponges and grow easily in an established, stable aquarium.

 

[DaJMasta]

I think it's a sponge, but a way to differentiate it between sponge and tunicate would be to poke it - tunicate would retract where sponge would not.

 

[Ratsinmyhead]

I think it's a sponge, but a way to differentiate it between sponge and tunicate would be to poke it - tunicate would retract where sponge would not.

I will give that a try and post back. Have plenty in the tank so no harm done. Thanks everyone for the replies

 

[jeffww]

Sponge. I have a lot of this one.

 

[Atrumblood]

I have a quarter sized one attached to my candy cane skeleton. Just recently it started to spread and I am finding little ones growing on the shaded parts of my rock work.

Can these guys become an issue?