Then I am guessing it is eating. If they work like a porcelin crab, the feathers collect the phyto and when is sucks in it is cleaning the phyto off the crown and eating it. A crab stick out its feathers into the current, then sticks them in their mouth to clean off the fans on their claws. The reason it never did that with cyclopese is it couldn't eat that, it was too big, so it wasn't actually collecting any food. Remember.. microscopic food here. We can't see it.