"Stress bands" ?

[ren]

hey guys just a quick question

on my turquiose discus, a friend of mine was told by his local fish shop that the black vertical bands on turqs are "stress bands" that they go dark when they are unhappy/stressed

is this true? i thought it was just their normal colourations

[Merrilyn]

Some turquoise do show bars all the time, even when they are in a very happy environment. Others have bars that come and go as the environment dictates.

Juveniles always show bars, and as they grow, some lose them and others don't, so it's not just related to stress.