he is pretty, if you really wanted to destroy the colonies, this one is not growing in the direct light meaning flipping the rock would bring ruin to the colony. a lot of sponges can not grow in the light for various reasons. Your chances of finding the right nudibranch to eat this if it exists are slim to none unfortunately, small sponges like these tend to only be able to be identified with microscopes and are dreadfully under researched.