Some kind of sponge?

[OldRed1]

Any thoughts? This photo is taken under 100% whites.

 

[WheatToast]

Do the holes close if disturbed? This is more characteristic of tunicates, as opposed to sponges. The star-shape of the holes also doesn't seem characteristic of sponges.
Similar looking colonial tunicates:

 

[JGT]

+1 for tunicates. I have ones like these in bright orange and their in/out ports will open and close periodically.

 

[OldRed1]

Do the holes close if disturbed? This is more characteristic of tunicates, as opposed to sponges. The star-shape of the holes also doesn't seem characteristic of sponges.
Similar looking colonial tunicates:

Thank you! I believe your ID is spot on!

 

[EeyoreIsMySpiritAnimal]

Any thoughts? This photo is taken under 100% whites.

You're finding the coolest stuff!!

 

[OldRed1]

You're finding the coolest stuff!!

I have been nerding out over my live rock, that’s for sure! Sadly, I think I just Id’d and removed my first bad hitchhiker—a whelk. I strive never to purposefully kill animals, but I was worried a whelk might do greater harm to the other inverts in the tank.

 

[EeyoreIsMySpiritAnimal]

I have been nerding out over my live rock, that’s for sure! Sadly, I think I just Id’d and removed my first bad hitchhiker—a whelk. I strive never to purposefully kill animals, but I was worried a whelk might do greater harm to the other inverts in the tank.

Whelks are bad news for sure!

 

[Sailaway]

I have been nerding out over my live rock, that’s for sure! Sadly, I think I just Id’d and removed my first bad hitchhiker—a whelk. I strive never to purposefully kill animals, but I was worried a whelk might do greater harm to the other inverts in the tank.

Same here. I’ve been staring at mine for a week because of all the cool critters on board!

 

[OldRed1]

Same here. I’ve been staring at mine for a week because of all the cool critters on board!

Have any pics of your inverts or plants?