Sponge

[jroescher]

If I remember right, it was something growing in one of the big tanks at FinAddict. No idea what it is other than a sponge. Whatever sees the light is dark marroon. In the dark it's white. It's about 12" top to bottom.

http://i38.photobucket.com/albums/e108/aquacop/Sponge.jpg

[ErikH]

That's a pretty sponge!