Remember that all inhabitants in Jim's Aquarium are juveniles, and many Juveniles vary from there Adult counterparts. In fact many juveniles make extreme transformations in there shapes/patterns that make them look like completely different fish(especially in the case of Angelfishes).
The fish you are referring to is indeed a juvenile French Angelfish(Pomacanthus Paru). Take a look here:
http://www.castlecomfortdivelodge.co...s/stripes.html
and here:
http://flowergarden.noaa.gov/french.html