White spikes on my Zoas. Sponges or worse?

[GigiHayward]

So my husband bought this zoa recently, however I'm new to this. He's not sure sure what these could be. We've only had it a week, they're not easy to pull off either. Done a RO soak and it's just caused half the polyps to not open again. Any ideas or recommendations? It's the white spikes coming out of the sides of the polyps

 

[ISpeakForTheSeas]

The only sponges I can think of at the moment that might look like that are Tethya spp. (you could google white Tethya sponges and compare what you see).

Just in case, though, do the spikes move around at all?

 

[GigiHayward]

The only sponges I can think of at the moment that might look like that are Tethya spp. (you could google white Tethya sponges and compare what you see).

Just in case, though, do the spikes move around at all?

They don'tove at all, quite solid and can't pick them off with tweezers really

 

[GigiHayward]

The only thing I can think it looks like is Aussie Spider sponge, but can that grow on Zoas?

 

[ISpeakForTheSeas]

The only thing I can think it looks like is Aussie Spider sponge, but can that grow on Zoas?

It's definitely not an Aussie Spider Sponge (the white parts of those sponges are actually zoanthids that live in a semi-parasitic-semi-mutualistic relationship with the sponge).

Few sponges can live actually on corals (corals typically defend themselves pretty effectively to keep things from growing on them and smothering them).

If it doesn't move and you don't think it looks like a Tethya sp. sponge, then you may need a closer up pic of one of the specimens in question for an ID.

 

[GigiHayward]

These are the closest pics I could get but even then my camera is still a little fuzzy. It's my husband's tank so he was the one dealing with it but while he's at work I thought I'd ask around. I'm even thinking potentially montipora eating nudibranch or zoa spiders? Just from image searches they're the two closest thing I can find either way we returned the coral to the seller. He didn't even bother inspecting it and put it straight back into the tank! (It was a shop bought coral) but for future reference if anyone does know, it would be nice to have that Information too.

 

[ISpeakForTheSeas]

I'm even thinking potentially montipora eating nudibranch or zoa spiders?

They're definitely not zoanthid eating spiders (Pycnogonids), and if they didn't move at all, they're not nudibranchs either.

My guess is still a Tethya sp. - something like the ones in the links below:

Tethya bergquistae - Wikipedia

en.wikipedia.org

Tethya gracilis Sponge

Tethya gracilisis commonly referred to as Sponge. Difficulty in the aquarium: There are no reports available yet that this animal has already been kept in captivity successfully. A aquarium size of at least 50 Liter is recommended. Toxicity: Toxic hazard unknown.

reeflex.net

Rambutan sponges (Tethya robusta) on the Shores of Singapore

Fact sheet with photos on flora and fauna of Singapore's intertidal shores

www.wildsingapore.com

 

[GigiHayward]

Hmmm I have no idea then, it definitely doesn't look anything like Tethya