Looks like a clam without a shell

[Tyler101]

So I have some of these things that look like bi-valves without a shell growing on my zoa rock. I thought it was a sponge but it reacts to movement and inflates/deflates around the day.

My guess is it's a tunicate but I wasn't able to find any that looked exactly like this so I figure id just double-check. I don't think it's harmful as it doesn't seem to bother the zoas around it.

Thanks!

 

[WheatToast]

Yup! Looks like a tunicate!

https://www.reef2reef.com/threads/what-is-this-growing-on-my-frogspawn-possible-sea-squirt.894690/

 

[Tyler101]

Yup! Looks like a tunicate!

https://www.reef2reef.com/threads/what-is-this-growing-on-my-frogspawn-possible-sea-squirt.894690/

Ok yeah it looks identical to the post you linked, thank you so much!

 

[Rtaylor]

Often called a sea squirt (but yes, a tunicate)

 

[Tired]

Oh, nice, a tunicate. Cool fact: those are chordates. They're in the same group as us. As babies, they have spinal cords. Then they glue themselves to rocks and turn into weird little bags of nothing.

I used to have one that looked pretty similar, and it did fine on its own. They're filter-feeders, so may not last long-term without supplemental feeding, but smaller ones have a better shot in aquaria.