While defending the Majestic Angel from the Blue Throat Trigger, I discovered that the Triggerfish has an unusual reaction to being touched on his sides.
When you make gentle contact with his sides, he immediately erects his dorsal fin and freezes. Once he does this, it is actually possible to push him around sideways in the water.
Anyway, in this video I catch him up against the wall of the tank and you see the reaction. He's free to swim away whenever he likes, but he stays frozen for quite a while! I've tried to do this by hand, but he doesn't like my hand to get that close and he keeps thinking my fingers are edible.

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400 gal reef. Established April, 2007. 3 Sequence Dart, RM12-4 skimmer, 2 x OM4Ways, Yellow Tang, Maroon Clown (pair), Blonde Naso Tang, Vlamingi Tang, Foxface Rabbit, Unicorn Tang, 2 Pakistani Butterflies and a few coral gobies
My Tank:
http://www.canreef.com/vbulletin/showthread.php?t=28436