found it:
Parts of its flesh are poisonous. It has the ability, when threatened or alarmed, to inflate its body to almost twice its normal size. It becomes alarmed when netted, therefore, use a container to transfer it.
so you could easily have an 8" round fish in your tank.
It will also eat invertebrates found in a reef tank. Its teeth are actually a fused beak-like structure.
your hermits and crabs may become meals