Can anyone tell me what this is?

[Knotyet]

looks like cob webs towards the bottom of rock with small holes in it. Kind of hard to see

 

[Reefer37]

looks like cob webs towards the bottom of rock with small holes in it. Kind of hard to see

Possibly a sponge. Hard to tell with just blues.

 

[mcshams]

This picture is really hard to tell. But if what I am seeing is correct, I believe that material is a sponge. IF it's a sponge, it's harmless.

 

[Timfish]

What they said.

 

[William Mumford]

Have the same exact sponge.

 

[Knotyet]

Didnt look like a sponge to me because theres a couple holes in it like something's inside of it ‍

 

[Timfish]

Just FYI but a lot of sponges have obvious exhalant pores that will look like holes

 

[Knotyet]

Yea your right that's what it is thanks

 

[Timfish]

. Sponges are real important in reef systems recycling the labile DOC from corals and alga. You can search Steve Tyree's articles and books and my posts here.