Is this some sort of sponge?

[targaboy78]

Hi gang,

I picked up 200lbs LS and 200lbs LR about 2 weeks ago and my tank is still cycling. These things were on the rock when I put them in the tank. Originally, they were flaccid but now they seem to be thriving. (I say thriving because they are growing and reaching towards the light - but what do I know... maybe they are trying to escape?)

Parameters;
Temp: 80F
pH: 8.1
SG: 1.024
NH3: 0.1 mg/L
NO2: 0.1 mg/L
NO3: <5 mg/L

I am thinking they are some sort of blue encrusting sponge (Haliclona sp. ?) In the bottom of my photo (six o'clock) there is a patch that resembles the Haliclona sp. on page 334 of The Conscientious Marine Aquarist. However, these sponges encrust rock and nowhere can I find a photo of one branching out.

OK, now my questions;

What are they?
Are they good or bad? I like the color and wouldn't mind keeping them.
If they are bad, what should I do next?

TIA,

Paul.

 

[targaboy78]

OK, I've ruled out 'silly string' because realistically how would that have gotten in there anyway? Otherwise, I'm still fishing for ideas....

My setup is going to be a reef tank one day but it is starting life as Fish Only (with LR). It would be nice to have some colour and movement on the LR so I actually don't mind having one fuzzy rock ( for now ) but I don't want it to spread.

Any thoughts about what it is? Ideally, if I can figure out what it is, I could decide whether it is staying or not. I could either find out how to care for it or find something that would eat it... Looks tasty enough.

Anyone?

 

[Corty]

The stuff on the bottom looks pretty common, I know it was discussed here before. I don't think I've seen the stuff on top.

If it doesn't kill anything, I'd like some.

 

[targaboy78]

After more research, I think that it is not Haliclona sp. but more like Leucosolenia sp.

http://www.biosci.ohiou.edu/introbioslab/BIOS173/images/lab1/leucosolenia.htm
http://images.google.com/images?hl=en&lr=&q=Leucosolenia&btnG=Search

The photo I originally uploaded was from my feature rock which is 22" x 10" x 10" weighing approximately 40 lbs. That is going to be in my main display, so the sponge has got to go.

Some of the smaller rocks with sponges may end up in my sump, maybe the biodiversity will be beneficial. I can deal with it there.

I'll update this thread in 6 months or so with the results of my experiment.

Paul.