Kilo is fine with my hand in the tank but when I try to cup him, he gets stress stripes like you would NOT believe. I suppose I better start working with him. When I switched him to the ten gallon he acted like I murdered him. He was pale and stripey.
I mean, fish get stressed in the real world so I don't worry too much over it. They're chased by predators and whatnot. It's perfectly normal in short bursts. It's prolonged stress (like days) that I think would be a real danger to a fish's health. If every fish that went 'AHHHHHHHHHHH!' got sick and died, there wouldn't be many fish left in the world.