Here's a couple of pics of my peanut worm. This guy has captured my attention for several months now. He lives in a rock that faces the front of my fuge and comes out to eat when I feed the tank. It's amazing how far he can stretch out from that small hole. Apparently, this worm appendage is introverted...it's like a glove finger that is folded inside of itself. As it stretches out of its hole, it extrudes outward (extroverts) and at the end are the feeding tentacles. It grabs the food in the tentacles and inverts back onto itself while withdrawing back into its hole.
Here he is in his hole (inverted mode):
He's coming out now, extruding his body:
Feeders are extended:
He is waving around trying to get food into his tentacles:
Still trying to more food into the tentacles before retracting:
His feeding tentacles are now retracting as he pulls back towards his hole: