Green bumps with tiny white dots

[Slything]

Need help identifying what this is in my tank. It has been slowly progressing over the past few months now with no sign of stopping. Originally did not think it was an issue but as you can see with the Zoa in the one photo it is growing directly onto corals.

I am not sure if this is what's causing that Zoa to die off or just bad positioning as the other Zoa's in the tank are thriving but it is the only one currently being invaded by it. I have also had torch head's die off that are covered in this. I recently went at it with a toothbrush and brushed it off everything I could. It is covering rocks though and not going to be possible to maintain manually.

 

[KJ]

Buble algea

 

[ilikefish69]

THE RARE SEA CACTUS!!!

No I think it's bubble algae, +1 to above comment. Don't pop them, or do.

 

[Slything]

THE RARE SEA CACTUS!!!

No I think it's bubble algae, +1 to above comment. Don't pop them, or do.

Not so sure it's bubble algae I have had that before and this is different. Bubble algae has a shine to it almost like a plastic bubble this seems different.

 

[WheatToast]

Almost reminds me of some growths of Dictyosphaeria, but this almost certainly isn't what you're seeing.
@Sharkbait19
@ISpeakForTheSeas

 

[Sharkbait19]

Seems to bumpy/spotted to be bubble algae - that’s about all I can help with though.

 

[ISpeakForTheSeas]

My first thought was bubble algae too, but now, looking closer at the photos, I'm almost thinking it's a colonial tunicate species of some kind - it's not unusual for tunicates to be translucent like this, and the spotting on the bubbles looks surprisingly uniform (which is not something I'm used to seeing in algae) which reminds me of colonial tunicates like Golden Star Tunicates (Botryllus schlosseri). I'm not sure though. It's interesting, whatever it is.

 

[Udest]

they look likesome sort of sea squirt look if you cant get some magnification on them

 

[ISpeakForTheSeas]

So, doing a bit of looking around, my guess is that it’s most likely a photosynthetic colonial tunicate of some variety from the taxonomic family Dideminidae (with photosynthetic members being found in the following four genera: Didemnum, Diplosoma, Lissoclinum, and Trididemnum). I can’t find many photos of a lot of these guys, and these guys have a surprisingly large range of phenotypic expression, so I don’t think I’d be able to pick a species, but I’d feel relatively confident in guessing it’s one of them. There is one other tunicate I know that looks somewhat similar as well that, to my knowledge, is not photosynthetic - Polyclinella azemai.

Some of the photosynthetic species that seem similar to me that you could compare against include (though photos are scarce for most): Diplosoma virens, Trididemnum cyclops, Lissoclinum punctata, Diplosoma aggregatum, and Diplosoma gumavirens.

 

[EeyoreIsMySpiritAnimal]

Buble algea

Nope

 

[EeyoreIsMySpiritAnimal]

So, doing a bit of looking around, my guess is that it’s most likely a photosynthetic colonial tunicate of some variety from the taxonomic family Dideminidae (with photosynthetic members being found in the following four genera: Didemnum, Diplosoma, Lissoclinum, and Trididemnum). I can’t find many photos of a lot of these guys, and these guys have a surprisingly large range of phenotypic expression, so I don’t think I’d be able to pick a species, but I’d feel relatively confident in guessing it’s one of them. There is one other tunicate I know that looks somewhat similar as well that, to my knowledge, is not photosynthetic - Polyclinella azemai.

Some of the photosynthetic species that seem similar to me that you could compare against include (though photos are scarce for most): Diplosoma virens, Trididemnum cyclops, Lissoclinum punctata, Diplosoma aggregatum, and Diplosoma gumavirens.

Have I told you how awesome you are??

 

[Slything]

My first thought was bubble algae too, but now, looking closer at the photos, I'm almost thinking it's a colonial tunicate species of some kind - it's not unusual for tunicates to be translucent like this, and the spotting on the bubbles looks surprisingly uniform (which is not something I'm used to seeing in algae) which reminds me of colonial tunicates like Golden Star Tunicates (Botryllus schlosseri). I'm not sure though. It's interesting, whatever it is.

Interesting, with the limited photos out there it's hard to tell for sure especially because the ones I am finding are much larger and grouped together. It sounds like these are harmless filter feeders? Which concerns me because I don't feel they are so harmless in my tank as they grow overtop of corals. Any ideas on how to fight these if that is what it is?

 

[ISpeakForTheSeas]

Interesting, with the limited photos out there it's hard to tell for sure especially because the ones I am finding are much larger and grouped together. It sounds like these are harmless filter feeders? Which concerns me because I don't feel they are so harmless in my tank as they grow overtop of corals. Any ideas on how to fight these if that is what it is?

Yeah, tunicates are generally harmless filter feeders, but some of them (like the Golden Star Tunicates I mentioned in my initial post) can be pretty invasive. Unfortunately, I don't really know how to get rid of these with them overgrowing corals. Being photosynthetic (thought to be obligately photosynthetic, not facultatively), I'd assume you could just black them out and starve them, but I don't see that going well for your corals. Not much really eats tunicates, and most of the things that do (that we have access to in the hobby) are not reef safe.

My best guess is that you'll need to scrape them out by hand (alternatively, you could probably inject them them with boiling water, lemon juice, kalkwasser, etc., or smear them with kalkpaste, but given the sheer quantity you're dealing with, I'd guess it would just be easier to scrape them out).