Any idea on this

[chubbyhubby]

Any idea on this was on rock when I got it months ago setting up tank . Was about 1/4inch when I got it and stuck to rock now it's about 1 1/2 long but today it's come loose. So any help would be great.
Thank dean

 

[kashman100]

Type of sponge. Pineapple sponge maybe

 

[chubbyhubby]

Do you no why it's come loose if it is a pineapple sponge

 

[KJ]

Google Tethya spp ?

 

[chubbyhubby]

Ok thank you il have a look

 

[saltyfilmfolks]

yes ball sponge. may come loose if its on the decline.