Weird sac thing...please help ID?

[limemittens]

Found a couple of these sac looking things on our rocks today. Want to find out what they are before it becomes a "problem".

Tried to get some good pictures. Hopefully these will help.

The sacs are a brownish white with little specks. Almost looks like the markings on some snail shells, but they are slightly transparent and pliable to the touch. Was thinking eggs of some kind, but we do not have two of the same species of fish in our tank, and I imagine our Wrasse would have made lunch out of them already if they were eggs.

Any thoughts?

 

[limemittens]

Here is another photo close up.

 

[seahorsedreams]

It's a sponge.... I see a siphon hole. Tunicates can also have siphons but they usually aren't that shape, or I should say , that's a common shape for a sponge. Does it react when you touch it?

Either way, a sponge or a tunicate, they are harmless.

 

[Kurt_Nelson]

Agree... some type of sponge. I have several in my tank right now. They come and go.

 

[Ziggy953]

Yeppers...nothing to worry about.

 

[melosu58]

Sponges. Good filter feeders.