Sponge? Shroom? Something Else?

[Donya]

I got a new piece of LR today. After I got it home, I saw these black-ish brown leathery things all over it. They feel fleshy/leathery, which doesn't say "sponge" to me all that much, but I could be wrong. They are overlapping and hang in pretty close to the rock even though they don't appear to be fully attached around all the edges (one lifted up partway in the current and went back down). They are irregularly shaped flat-ish blobs that have little volcano-like openings in the center. As far as I can tell, it's only one opening per "individual". This is the best my cruddy little camera can do for the moment, sorry...

The largest one is 1" in diameter, the others are smaller, probably 1/2" or less diameter. They look fairly shroom-ish, but the problem is there are some that appear to be slightly fused together at the edges, and they do lie extreemly flat against the rock (not like the shrooms I've seen in the stores).

 

[Mr Miagi]

I have no real idea from those pics sorry. They sounds like shrooms, but closed shrooms. They might be fused because they are in the process of fision. Wait a few days and see what goes on, if they are shrooms, they should be open in a few days. If they were kept in the dark, plain holding bins that normally hold LR, they probablky have temporarily closed. One of my fluffy shrooms left a baby shroom after "walking" and its under the larger ones shadow. Its still a small black, slipery "nipple" on the rock.

There 'volcano" like openings sounds like a classic sponge. Its called the osculum, an opening where water can flow out from the sponge after being drawn in through the walls. They can feel fleshy, and come in thousands f shapes and colours. An ID is nearly impossible with sponges.

With the naked eye, can you see any holes in the subject? Like a sponge?

 

[Donya]

The only holes visible are the large ones. I looked for smaller pore-like structures, but couldn't find any. It just seems to be a smooth surface with one opening. I will see if I can get some better pictures; it's tough with that camera because it always picks up a lot of color onise on closeups for some reason.

 

[Donya]

Just discovered a baby fanworm near the strange black things The rock came from a well-established tank, so it won't have been in the dark for any abnormally long time. If it is shrooms I hope I havn't done something to really stress them out and make them stay closed

 

[Aquascaper]

Sounds like a sponge or tunicate IMO

 

[Donya]

Found a bunch growing under some macro on the rock--looks like sponges since it's a big chain of them connected with no sign of splitting or anything. Just a big black blob with a lot of little "volcanoes" all over.

Also looks like I have a little hydroid thing. It's only 4-5mm and closes up when a shaddow goes over it, but I think it might be an Aiptasia. Looks suspiciously like one, it's just so small...do Aiptasia come that small? I'm used to seeing them much bigger, even newly budded ones. Shape-wise it matches Aiptasia.