duncan parasite??

[mizimmer90]

I found some holes on my duncan with what looks like very very tiny feathery things in them (can't tell if its a creature or some mucus from the coral). pictured are 3 of the holes:

Background:
My hermit crab has been sitting on my duncan for the past 2 days. I have been worried that he's eating the duncan, but after closer inspection I found the holes. Does anyone know what this is? Parasite, or is the crab actually to blame here?

 

[mizimmer90]

OK definitely a parasite. Difficult to capture with my cell phone but you can see two feathers spinning around and opening and closing. Anyone know what this is? Will the hermit crab eat them? See attachment