Coral ID

[CoMMaNdeR]

This is round like circle. Its like some kind of sponge or hard algae. It's slip and a bit hardy but if you press it it squash.
It is on a piece of live rock. It is dark green. I smell it to check if it is dead, but no smell so I guess it s alive. It didn't expanded, remained always the same size.

Here are 2 pictures:

 

[deansreef]

valonia?

 

[CoMMaNdeR]

Don't know what it is. This thing is about 3 inch.

If is Valonia is it good to have ?

 

[RicksReefs]

if it were valonia (which is green) it would have exploded when squished. I'd say it's a sponge, especially if you can see at least two holes (or tons of micro holes) in it for respiration and feeding.

 

[RicksReefs]

and valonia is a pest algae, so no, it's not a great thing to have.

 

[magnum420]

I'd say it looks like a ball sponge. See this link..

http://www.bio.fsu.edu/coleman_lab/florida_middle_grounds/middle_grounds_sponges.php

Third to bottom on right side.

 

[Ludwigia73]

Ditto on ball sponge. Definitely not valonia.

 

[CoMMaNdeR]

Today I checked this thing and there are no tiny holes...Do you think is some kind of algae ?