I usually just call stuff like this a sponge, but....

[Frick-n-Frags]

I'm starting to wonder. I have two of them in med flow in the shade. This one is smaller, but better to photo, maybe an inch long 3/4" wide. Those dark channels get wider and narrower.

I only have two guesses for this weird crap: sponge, colonial tunicate. but P U N T !


under the VHO's:
http://www.rusynyk.com/coral/weirdspongeVHOlight2.jpg

with flash:
http://www.rusynyk.com/coral/weirdspongeFlash.jpg

flash pic photoshopped by upping the brightness and contrast:
http://www.rusynyk.com/coral/weirdspongeFlashPshopped.jpg

[SDguy]

Yup, I vote sponge.

[Frick-n-Frags]

-my only ? is why are there rows of looks like individual inlets all hooked to a big common outlet? which is why I am wondering colonial tunicate, but the shape's weird, oh well, I haven't seen everything either.

[SDguy]

Probably the entrance/exit holes it uses to pass water and filter feed. (I forget the scientific terms...been a while since UCSD :D )

[spleen93]

I thought tunicate too but it could be a sponge, I suppose.

Spleen

[SDguy]

Don't tunicates specifically have one hole in/one hole out? And they always seem to have a pretty classic tunicate shape, even the colonial ones.

[LeslieH]

That looks like a species of Placospongia. These are called alligator sponges because of the hard plates crossed by fissures, much like the plates in an alligator's hide. The ostia (inhalent pores) can be seen in the fissures plus the one large oscule (exhalent pore).

[Paintbug]

its a colonial tunicate, i couldnt tell you the species though :)

[Frick-n-Frags]

:D, I don't feel so bad.

What really gets me is that the creature can make those ?inlet pore? channels wider and narrower.

[Salamander]

I had some of those in several colors. When I touched them they closed up the holes and fissures. Not quickly but they closed.

[spleen93]

If the holes and fissures close when they are touched, wouldn't that argue for tunicate rather than sponge? Though I do agree with Leslie that the pictures of Placospongia do look similar ...

http://perso.orange.fr/sulawesi.biologie.sous-marine/SPONGIAIRES%20OU%20EPONGES/images/previews/preview18.jpg

Spleen

[LeslieH]

Placospongia is one of the few sponges that react to touch by contracting. The overall appearance is very striking and characteristic.

[Frick-n-Frags]

awesome!