Identify please

[m2736185]

I have a Cacoon type thing that has been growing on one of my rocks, It has been getting bigger and bigger it has a few "holes" where a jelly like "tenticle" about 2mm sticks out. Any idea what this could be?...

 

[bertoni]

Looks like barnacles to me. It also could be a sponge with a commensal worm. Can you get a sharper image?

 

[Evergreen]

It's either a spronge or a group of tunicates.

 

[Paintbug]

i would go with tunicates on that myself.

 

[bertoni]

I tend to agree after looking a bit harder, but the tentacles are interesting. Neither a sponge nor a tunicate would have tentacles, right? A commensal worm or other creature?

 

[Paintbug]

the tunicates i got on my LR had a mouth in the holes. some days it would almost come out. but not often. i never seen any tenticles myself there may be some that do.

 

[m2736185]

hmm well i just noticed one growing on another rock....is it something that should be removed or what?

 

[bertoni]

I don't think they'll harm anything. Up to you whether you like the way they look.