The tube nem, like mel says really doesnt move, however it turn directions if it is not secured, a couple days ago I saw it sting some Blue dot zoas I have, I moved itsd direction and today was right back facing that way. I had to move the zoas. Most fish know to stay away, those that dont DINNER, same w the lobster. But overall, very nice looking creatures, not too much risk.
P.S. - Aquarium depot has a new tube nem, same color, not as big. Malice, the tank is 28 bowfront!! Thanks!