Mystery on live rock

[coralreefer123]

Florida live rock has these pale yellow holes on it. What is it? Zoas?

also what is this (circled) algae or mushroom growing on the rock? It is fluorescent under blue light.

 

[eag]

Hmm it kind of looks like dead, discolored barnacles.

Not sure about the thing in the circle. Maybe Coraline? I have some that fluoresces bright pink

 

[eag]

Some of them appear to not have a hole though and are instead depressed ...

 

[Uzidaisies]

Looks like some sponges, and some dying coralline algae.

 

[eag]

The more I look at it, the more they look like some kind of sack ... Like popped bubble algae

 

[coralreefer123]

Thank you all for helping. Here is a flash picture of the yellow stuff. It’s on lots of the rock you will have to zoom in

 

[coralreefer123]

Another pic

 

[WheatToast]

I am stumped on what those yellow bumps are as well...
Maybe this person can help: @Isopod80

...and some dying coralline algae.

Looks more like dying Peyssonnelia to me. It is another calcareous, encrusting algae and is harmless. I believe it looks beautiful alongside Coralline.

 

[Isopod80]

They appear to be any one of several yellow sponge varieties common to Florida live rock. I can see what appears to be the incurrent siphons on a number of them. It's common for young ones to begin life in holes and crevices. However, if they are hard to the touch then they would be a form of benthic formaniferan. Another filter feeder that can be mistaken for sponges at times. The bright orange algae is dying corraline. Many varieties appear florescent under blue light when dying. I wouldn't expect Peyssonnelia to glow orange in the same manner.

 

[WheatToast]

I wouldn't expect Peyssonnelia to glow orange in the same manner.

If I remember correctly, I believe it is Peyssonnelia, not Coralline, that glows orange when dying (under white light).