Essential Notions about ZOANTHIDS can be found here: -
FRAG No 1: When possible we always favor the Natural Method of mounting frags directly on their permanent rock support without using adhesives or even rubber bands. So this one was fixed inside a cavity on a piece of Dry Rock with coral sand filling the gaps... to prevent it from drifting away with the currents.
To better understand the Natural Method of fragging
see following link: -
FRAG No 2: It started as a single polyp in July 2018 and soon added a second fast growing one
FRAG No 3: Added in August this colony starts to show pink dots on oral disk