Anyone know what this is?

[koolademan]

Would anyone know what this is? I recently am starting a reef tank and bought this live rock from a pet store.

 

[afboundguy]

Tough to 100% sure but looks like a small sponge IMO...

 

[absolutecarrot]

Looks like a sponge I have those to

 

[koolademan]

Thank you for the response! So you wouldn’t think it’s aiptasia? If it’s a sponge is it harmful to fish or corals?

 

[absolutecarrot]

Thank you for the response! So you wouldn’t think it’s aiptasia? If it’s a sponge is it harmful to fish or corals?

No it’s harmless even cleans you water, as long as it’s not bothering anything it will be fine

 

[koolademan]

No it’s harmless even cleans you water, as long as it’s not bothering anything it will be fine

Thank you so much! I was worrying a lot before since this is my first attempt at a reef tank

 

[afboundguy]

Definitely doesn't look like aiptasia...

 

[mvallee]

tough to tell from the pictures but look up hydroids in reef tank images and see if they look like this. It is one of those pests that comes and goes. I only say this because it looks like the tips are fuzzy looking

 

[gobyvin]

Agree with the sponge ID. I have had these in large numbers in tanks I have kept over the years. Syconoid sponge. Term refers to the shape of the colony of cells, like a barrel with a common shared output pore. In this specimen, that is the hole at the top surrounded by spicules, or silica-based structural elements, secreted by the individual cells in the colony. These are a great sign if they continue to proliferate. They like low steady flow zones, like sump space or in crevices.

 

[Patrick.S]

Pineapple sponge I think.