ID: Sponge, egg sac, what is this?

[rookie07]

I discovered this on a rock in the back of my tank. There was always low lighting on this area.
There is a "sac" on each side of the grey tongs...and there appear to be many smaller "sacs" making one big "sac"

There appears to be extra "skin"...it kind of sways back and forth in the current, but not much.

I thought it was a sponge, but then it looks like it popped, or open, so now im concerned.

3rd Picture is the best

Any ideas?
Thanks

 

[Domboski]

It looks like some sort of tunicate colony. Google image search golden star tunicate or tunicate colony and see if anything looks similar. Some tunicates can look like sponges.

Try image searching this as well: [FONT=Verdana, Arial, Helvetica, sans-serif]Botryllus schlosseri[/FONT]

 

[rookie07]

Doesnt really look like any of the things you suggested...it appears to be more of an "empty sac", as if it once held eggs, etc

 

[Domboski]

Possibly :scratch: Your pictures and description make me think tunicate though. It may be easier to ID with a better pic.

 

[Domboski]

These look real similar to your pics to me too: http://www.wetwebmedia.com/AscidianPIX/Alans squirts.jpg

 

[rookie07]

mine appears to be falling apart..as if it is dead, and is now breaking down...if that is the case it could have been a tunicate...but why would they both be dead, and now breaking down. They were not on the rock when the rock was placed in the tank...and there was always light on these spots...so why would a tunicate grow in such a location?

 

[Domboski]

I have tunicates in my tank that grew out of nowhere (3 different kinds) Two of them growing where there is plenty of light.

It is strange that an entire colony would grow and then suddenly die off. Do any of the openings close when you touch them?

Do you have any paired fish? Any recent additions of fish that may have been wild caught? Do you have seahares or nudibranchs?

 

[rookie07]

I had a nudi..but have not seen it in weeks....no paired fish...no change when touched with tongs.

I added a few fish in the last 3 months(flame angel, yellow coris, xmas wrasse)

 

[Mr. Softy]

Looks like some of the tunicates i see growing on the boat docks around LI. I used to keep a batch many moons ago in a local only tank.