What is on my decorator crab?

[jordanrb]

At first I thought it was a chunk of coral but now that it has grown I have no idea. There are a few.

 

[Uncle99]

I see Aptasia, GHA and some type of simple sponge.

 

[jordanrb]

Pulled one off and it shriveled up and closed the tube like vents sticking out. It is very hard.

 

[jordanrb]

I see Aptasia, GHA and some type of simple sponge.

Yeah there is one small aptasia that is in between legs so I can never grab it before it retracts. Im more concerned about the large bubbles. They look almost clear with tube like vents randomly sticking out. If you see my other picture I pulled one off. It almost shriveld up and retracted and turned very hard. I have a bright red sponge in my tank but this doesnt resemble anything like it

 

[ISpeakForTheSeas]

Yeah there is one small aptasia that is in between legs so I can never grab it before it retracts. Im more concerned about the large bubbles. They look almost clear with tube like vents randomly sticking out. If you see my other picture I pulled one off. It almost shriveld up and retracted and turned very hard. I have a bright red sponge in my tank but this doesnt resemble anything like it

Sponges are quite varied, but in this case, these are solitary tunicates (A.K.A. sea squirts) - harmless filter-feeders.

 

[jordanrb]

Sponges are quite varied, but in this case, these are solitary tunicates (A.K.A. sea squirts) - harmless filter-feeders.

It 100% is a tunicate. While I cant find an identical match, a lot of images online resemble the ones on the crab. Very interesting. I kind of feel bad for taking on off now. Thank you!