Found this weird creature in live rock rump.

Pete Hammersley · Mar 4, 2020

This is really old live rock, and when transferring it from my old tank to the new sump I found this.... when I pressed on it with my finger it squirted out water from both ends like a cows udder! Any ideas?

good.reef · Mar 4, 2020

Pete Hammersley said:
This is really old live rock, and when transferring it from my old tank to the new sump I found this.... when I pressed on it with my finger it squirted out water from both ends like a cows udder! Any ideas?

Looks like some sort of sponge or sea squirt...

KJ · Mar 4, 2020

Tunicate.

Pete Hammersley · Mar 4, 2020

good.reef said:
Looks like some sort of sponge or sea squirt...

Thanks.

Pete Hammersley · Mar 4, 2020

Thanks. Is it safe to keep? Or get rid?

vetteguy53081 · Mar 4, 2020

+1 on tunicate. Safe filter feeder but some do not want them in system or to multiply. You can fill cavity with gel glue

good.reef · Mar 4, 2020

Pete Hammersley said:
Thanks. Is it safe to keep? Or get rid?

Honesty I have all kinds of sponges and stuff growing. It's not harmful, they actually filter the water. I doubt it would spread uncontrollably. Things like this are the type of things people like having in cryptic zone filtration. If it were me I would not kill it.