I bought a orange tree sponge a little over a month ago. I have seen this tube looking thing on the bottom of it and figured it was an old skeleton that the sponge was on I have that side of the tank dimly lit for the sponge. I turned my bright lights on today to clean my glass ect and saw the little mouth close and open again so it is alive. I have been googling for a while and can't find anything other then a maybe a type of tunicate? Any thoughts? Do I remove it?
