What is this black hitchhiker...a sponge?

[DHill6]

Spotted this tonight with a flashlight. I just purchased Real Reef Rock from Pacific East Aquaculture. They keep it in with their baby clownfish tank. It wasn't there yesterday. Remove it?

 

[Ashish Patel]

My guess is Chicken liver sponge!

 

[KJ]

A sponge will not grow overnight, I don`t know what it is ,it is hard to tell from these pics.

 

[KJ]

Is it moving around or is it stationary?

 

[DHill6]

A sponge will not grow overnight, I don`t know what it is ,it is hard to tell from these pics.

Exactly what I thought. Having the rock out of water, chiseling it, I didn't notice any black coloration.

 

[DHill6]

Is it moving around or is it stationary?

Stationary, hard, easily chiseled of the rock.

 

[DHill6]

My guess is Chicken liver sponge!

Good guess, I never heard of such a sponge, but I looked it up after your suggestion. Using a magnifying glass and flashlight, it looked see through with black spots, funnel shaped. The picture doesn't show this. I chiseled it off the rock as not to deal with black rocks. Good thing about this man made rock, chisels easily.

 

[DHill6]

Same real reef rock, now it's changing darker bumpier areas, any ideas?