Looks like Botrycladia (red grape caulerpa) macro algae, but it's a rough pic.
Sorry, perhaps I am mistaken but from his responses it seemed like he was confused about two different things. We need better pics and perhaps circle what you are confused about.
Sorry guys the thing that retracts is so small I can't get it into pic. It looks like a feather duster and retracts to loud noises but I can't show ya so I'll have to wait. This branch thing feels like a tree lol it's very hard