Straight animal ID

[OrionN]

Anybody know what this is or who we can ask about ID? This animal is not in my tank. A poster asked over at RC. I have no idea and post it here for more exposure. I asked if it move and if it is an animal or plant and this was reply:
"the animal basically rests on the bottom of the ground and glass, moving if the current carries them away. does not climb on corals, only one other on the reef itself.

 

[OrionN]

Sorry, misspell and I cannot correct it.

 

[Boreas_SA]

Tethya sp. sponge?

 

[OrionN]

It looks like a new (to me) algae rather than an animal.
It seems these plants, or the symbionts have chlorophyll and are photosynthetic. I don't see a mouth. They seem to reproduce by budding, and obviously expose to light and need light to growth.

 

[Boreas_SA]

Tethya seychellensis is symbiotic with an algae, most probably other species too in the genus. But only a guess, probably a chance it could also be a type of turnicate or even flatworm.

 

[Cell]

@ISpeakForTheSeas

 

[ISpeakForTheSeas]

Anybody know what this is or who we can ask about ID? This animal is not in my tank. A poster asked over at RC. I have no idea and post it here for more exposure. I asked if it move and if it is an animal or plant and this was reply:
"the animal basically rests on the bottom of the ground and glass, moving if the current carries them away. does not climb on corals, only one other on the reef itself.

Tethya sp. sponge?

@ISpeakForTheSeas

Given that it only moves when carried away by the current, that would eliminate it moving on its own or being firmly anchored down somehow.

A Tethya species is a good guess, but it doesn't sit right with me - the growth looks different than the typical growth I've seen on Tethya sponges, and the critters look more slimy/shiny and translucent than the matte, opaque coloration typical of Tethya sponges in water. Regardless, microscope pics of sample could say for sure on that front - there are some really good pics out of various Tethya species' spicules, so it would be easy to compare against if the critter shows any spicules (and if it doesn't, that eliminates sponges as an option).

I do agree these seem to be photosynthetic - it's been a while since I've looked into photosynthetic tunicates, but something like Trididemnum cyclops or Diplosoma aggregatum seems like a decent candidate to me.

Any chance the OP has clear pics of the topside of one of these rather than the bottom?