I’ve had this decorator crab for a few months and it has some serious coral/sponge growth on its shell which has really taken off since I added it to the tank.
Can anyone she’d some light on what kind of coral or sponge this little dude has growing on its shell?
Could be a colonial tunicate. The ones I see on rocks usually are somewhat clear, so you can see more clearly each individual mouth, but if the flesh is just opaque yellow, a colony of them could look just like that.