Many copperbands unfortunetely die during this stage, they just never get eating like they should. Even down the road these fish tend to be very fragile. I know of many people keeping these fish (responsible reefkeepers), and while they get along fine for quite lenghty periods of time and appear healthy, one day they just stop eating, the next, they are dead. I have heard this story repeated time and again, and no reasonable explaination is usually to be found. It is a shame to see these beautiful fish for sale in every LFS you stop in as it is in the greater majority of reef tanks that they experience greatly shortened lifespans and perhaps much unnecessary suffering. This is not to say some people do not have great luck in caring for these animals, but I fear it is the larger majority of these fish that are sold that find a less fortunate fate in our captive reefs.
-Dave