ID challenge perhaps?

[flashlink]

ok i cant figure out what this is...

the fuzzy disk thing, with the hairlike stuff coming from it
this is the best angle and clarity i can get.. it actually is shaped like a clam in that there is another disc on the other side of it that also looks hinged...he would be a hitchhiker, i noticed him after rearranging rockwork...

anyone have a clue...?? good or bad??

 

[romunov]

It's a sponge, probably calcerous.

Sponges
How to ID a sponge and why should you just call it what it is - a sponge
Sponges: A Bunch of Holes Held Together by Some Cells
Sponges - pump-filter modules through space and time
Some Truths about Sponges

 

[flashlink]

had no idea sponges varies so much and could look so different! thanx for the quick response romunov!

 

[hairymushroom]

Thats actually an oyster, check to see if it closes it you block light over it or if you touch it.

 

[RicksReefs]

it's a sponge.

 

[flashlink]

ok then i will see if i can touch it...