"sal" wrote in message
...
They /look/ like tunicates, but I doubt that's what they are . They're
probly some sort of sponge. I've had these in my aquaria before and I've
seen
them growing on the glass in a lot of live rock holding tanks in pet
stores. They shouldn't be a problem in a fish-only tank. Most likely you're
not
seeing them in the actual tank because the fish are cropping them before
they can grow. That's just mho.



They are sponges, but for the life of me I can't remember the species name.
Harmless.


--
Toni
http://www.cearbhaill.com/reef.htm