I actually doing the same thing. Put a piece of rock from my QT system to the DT when I need to remove some of the Fauna and Flora from the QT system. This is what happened to my rock as I place it into the DT from my QT system over 3 days.
Day 1. the CBB hunting pods and worms on the rock along with the Foxface having a feast. One can really see the round stomach of the Foxface
Day 2
Day 3. The rock will go back to the DT. Not everything was wipe out so it will regrow quickly.
The tusk looks like he missed out!