What is this?

[n00bReefer]

Hard to get pics but it's a slug like thing with antennae.

Just saw it now.

 

[mushrommy]

Hard to get pics but it's a slug like thing with antennae.

Just saw it now.

I see rhinophores, so it's a nudibranch, idk what type.

 

[ISpeakForTheSeas]

That’s a nudibranch. If you can get a clear, top-down shot of its back under white light, that’d make ID’ing it easier. As is, I’d guess a Dermatobranchus sp. (not reef safe - they eat octocorals (soft corals, gorgonians, etc.) including GSP.

 

[n00bReefer]

I'll try here shortly. Lil bugger just popped up! Always a surprise to SW tanks.

 

[n00bReefer]

That’s a nudibranch. If you can get a clear, top-down shot of its back under white light, that’d make ID’ing it easier. As is, I’d guess a Dermatobranchus sp. (not reef safe - they eat octocorals (soft corals, gorgonians, etc.) including GSP.

These the same things that eat aiptasia?

 

[n00bReefer]

Added additional photos.

 

[ISpeakForTheSeas]

These the same things that eat aiptasia?

They’re both nudibranchs, but the ones that eat Aiptasia are Berghia sp. nudibranchs. In this case, I'd check any softies in your tank and see if you find more (Dermatobranchus typically come in on Green Star Polyps from what I've seen).

The pics aren't super clear, but my best guess at the moment would be Dermatobranchus diagonalis.