yellow tang

[angelofdeath132]

i posted this in the fish room also but i need help so i'll post it here too. my brother-in-law bought a yellow tang yesterday,the fish looked awesome in the store,very active,no blemishes,eating well. so this morning he gets up and the tang has a white stripe running freom head to tail but he's still very active and still eating well, any ideas,stress from moving to a new tank?

 

[tygerfifteen]

it's normal it goes away when the light is on.
Mine does that every day some kind of defnese mechanism so they are harder to see at night for the predators.