What the heck is this thing on my sps?

[jun41]

I've seen this thing clinging onto my coral's plug for a couple weeks now and I decided to pull it out and see what it was. It looks a little bit like a sponge. It's kind of hairy and has one little "mouth" at its tip. It's a little bit hard to see. I can take more pictures if I have to.

Does anyone have any idea what this thing is?

 

[Anonymous]

It's a member of Porifera ( sponge ), harmless.

Regards,
David Mohr

 

[wade1]

Nice to have in the tank as they provide a bit of extra filtration of particles and organics (termed cryptic filtration).

 

[Anonymous]

Didn't I read an article a while back that mentioned a guy who squashed one of these things with a bare finger and spent an evening in exquisite pain? Harmless to the tank perhaps, but worth a bit of caution?

Perhaps I am misremembering. I'll search it.

Btw. I have half a dozen of those exact things in my tanks too. I am stealing a chunk of your picture if you don't mind. My picture of it sucks.

 

[jun41]

That's fine. And regarding the poking thing, I poked it a bunch of times and I feel fine. When I poked it it felt a little bit like a longan, if you know what that is.

 

[wade1]

Many sponges have some very potent toxins associated with them, but no stinging mechanism... so if anything the guy may have had a cut or some open wound on his finger. It is possible. Just not terribly likely.

 

[John_Brandt]

It appears to be a sponge. Many of these have silicate spicules (like tiny needles) throughout the animal that will sting like crazy if you get them jammed into your skin. Same defense that bristleworms use, and with the same effect.

 

[Anonymous]

Didn't I read an article a while back that mentioned a guy who squashed one of these things with a bare finger and spent an evening in exquisite pain? Harmless to the tank perhaps, but worth a bit of caution?

Perhaps I am misremembering. I'll search it.

Btw. I have half a dozen of those exact things in my tanks too. I am stealing a chunk of your picture if you don't mind. My picture of it sucks.

I remember that, too. What he squished was a nudibranch or sea slug of some sort.

 

[Anonymous]

Sponge of some sort

 

[SnowManSnow]

Sponge.. I had a rock covered with them.. they all died off after I put good lighting on my tank. From my experience with them.. they wont hurt anything, although the ones I had did multiply quite a bit.

B

 

[wade1]

Most sponges actually assist the tank by acting as additional filtration... they filter a large volume of water and remove many of the dissolved organic compounds from it in the process.

See: cryptic filtration