Another tiny and virtually undetectable creature is the Orange Ball Anemone. It is actually from the mushroom family, and not an anemone at all. However, due to its appearance, it was named accordingly. I have found these scattered throughout my tank, usually closed up all day long but opened up at night when the lights are out. This particular one was tucked in between some zoanthids that happened to be closed. It's kind of neat looking, and it would be nice if they were larger so they could be enjoyed properly. Reef-safe.
While sold to me as a Ricordea, these are actually Frilly Mushrooms from Tonga. Identified as Lavender Frilly Mushrooms, they have lovely purple tips. Frilly mushrooms are recognized by the extended tentacles that branch out in two or more appendages. They grew nicely under PC lighting, and didn't split or make more in my 29g. Each polyp grew to about 3" in size. If enough food is in the tank, the entire mushroom will fold closed to trap the food like an anemone would. Later these were moved to my 280g and reproduced into a purple carpet.