Blue soft coral ~ leather, sponge or what?

[AquaDaddy]

I can't remember when we got this, but I'm pretty sure we were told it's a small piece of blue leather coral. At the time, we didn't question it, but just for kicks, the other day I tried to get a better identification and well, could not find anything, but saw some sponges which look similar.

Any idea what this is? Good/bad?

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[Heartbreak7]

Looks like a harmless plating sponge to me.

 

[Derbird]

Kind looks like blue ridge coral to me. Does it have a hard skeleton?

 

[AquaDaddy]

Kind looks like blue ridge coral to me. Does it have a hard skeleton?

@Derbird I don't think so. I just looked that up and don't remember seeing any polyps at all. It does get pretty shiny on occasions, which is weird.

 

[scchase]

It is a photosynthetic plating sponge, Collospongia auris

 

[AquaDaddy]

Should I keep it? Looks okay in the tank, and doesn't seem to cause harm.

 

[scchase]

Not a super fast grower but can overgrown stuff if you don't pay attention

 

[norfolkgarden]

Keeper. Blue plating photosynthetic sponge.
Difficult to kill.
Fragging can be done with a small knife or just your fingers ripping off a piece.
Like plating montis, it can shade out other corals.

 

[AquaDaddy]

Awesome. Thanks