What the heck are these?

[pjewett]

I have maybe 2 dozen or so of them and they seem to all be in low light areas..especially around my intank fuge. They look like pale pineapple shaped things.

Anyone have an idea? Are they good or bad?

 

[QUESTIONMARC]

sponge. they attach to the glass. they help filter. they are good guys.

http://www.melevsreef.com/id/sponge.html