Anyone know what this is?

[pars]

Hi all. I'm new here.

My 125 gallon tank at work has been sprouting something new on an overflow the last few weeks. Initially I thought it was some type of tube worm -- I have a lot of (what I think are) tube worms in this tank that shoot out webs whenever they become irritated. But this thing is growing fairly rapidly. it is now about 3 inches in size. Looks soft. Hole in the middle. I've never seen anything coming out of the hole -- even at night. I've come back to the office after lights out just to check.

I'm not sure if it matters, but for the time being I'm stuck using tap water so the parameters are horrible (very high nitrate and phosphate) -- and yet the tank seems to be doing great with things growing quite well.

Attached is the poor iphone pic.

Any thoughts?

Thanks.

 

[psychofishy]

well...

On the back I see a little asterina starfish (often harmless)
The Tube worms that shoot web's are Vermetid worms, also mostly harmless.
the growing thing with the hole in the middle is hard to describe from the picture, but my guess would go towards a Tunicate or a sponge of sorts.. both harmless

 

[pars]

Tank is about 6 months old. Normal to start growing sponges on a back wall not adjacent to rock? They must be freely mobile in the water column?

 

[DEEP BLUE SIX]

It's a Vermetid Snail. They don't look like what you'd typically consider a "snail".
Their tubes are similar to some kinds of tube worms. But they are not that animal at all. They live in brown or white "Tubes" which they create themselves. Sometimes a stringy mucous comes out the opening like webbing. Basically, they are harmless for the most part. Especially if you only have 1 or 2 of them depending on where they are located. They could grow anywhere. Sometimes the "web" mucous is annoying looking.. sometimes in a dense populated tank it can also "irritate" certain corals it touches. It's up to you if you want it or not. You can either use a glove and break the tube off(which there is no guarantee one may not grow somewhere else if there was something to spread it's offspring) OR perhaps more effective, super glue the end hole. It will kill the Vermetid snail. Then you can remove the tube later if you want. It's not a real threat, can't sting or do any aggressive damage to anything. But as I said, the mucous webbing sometimes irritates some corals it touches and sometimes if a lot of "webbing" comes out, it can look annoying in some tanks depending on the natural placement of where the animal is living. The snail stays in the tube forever. You never actually see it.. the mucous may be how it gets things from the water column to eat. Or may be something else..

 

[DEEP BLUE SIX]

Not sure how yours is now or if they are ever different- when forming/growing.
But usually the tubes of these particular animals themselves are very hard in structure once settled in. It protects the animal inside.

Your picture is kind of hard to see, for someone that doesn't know what your talking about. Your description helped me pick it out in the photo. Your picture is pointing directly at the hole end of the tube. Doesn't really show the tube itself as in a side view. But I got it.
It's almost dead center of the pic. On a piece of small rock or a plug..?

 

[Gary Majchrzak]

big thing with hole in the middle of pic is a sponge

in any case, don't lose sleep over anything in that pic!

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