Interesting "sponge"

[tebstan]

So I've got this sponge. Sold as a "Red Knob," whatever that means. I've also got a "Red Velvet," and both have been doing fine for quite a while now.

But the knob sponge, it likes to roam...

Turns out it's on a live mollusk of some sort. I was wondering why the sponge had a crack in it, with a mysterious tendency to move and then attach with ferocity.

I'm pretty pleased with this, for the most part. It's odd, and that's fun. But it does pose some questions. Does it wander around because it's unhappy, or that's just its nature?

It clearly prefers dark spaces, which are hard to get into at its size. Would a mollusk be okay on rock, or should it be on the bottom? I've got a nifty little cave about halfway up in the tank I want to try it in, but I don't want it tumbling back where I can't retrieve it.

I'm going to stick it in the sump for now. I'd rather have it in the display tank where I could see it, but I'm not sure what to do with it.


Sorry about the bad shots, couldn't get good lighting over the make shift holding tank. (No, it never touched air.)

Sponge side





Mollusk side

[justahobby]

Mollusks like this one are not dependent on light like a crocea clam would be. From my own experience they tend to prefer wedging themselves into rock crevices and feeding after lights out. It's kind of a tough call on placement. The fuge may let you watch it more closely, but the display would offer a larger/ more natural environment.

[hobogato]

yep, this may be a scallop of some kind. they are filter feeders, so they will eat some of the same things as the sponge. you probably should start adding phyto as well if you arent already

[tebstan]

Well, I sucked it up and took a risk. I moved the sponge thing to the upper rock work.

There's this weird shaped rock with a natural cave, but a sponge sized hole underneath it. I was worried it would retreat into the hole and I'd never see it again.

Instead, it shimmied up the side of the cave and attached to hide under the lip of the rock! I couldn't be happier with this. I have a sponge mollusk hanging vertically in a cave.



The weird lighting is because I used a flashlight to snap this pic. I was so excited I didn't want to wait until sun-up. (That's halimeda growing on it, until the tang gets to it.)