Twenty plus years ago they called them black arowannas. Sometime in the 2000's the name got changed to blue. I don't know who did it but even the shippers from south america now call them blue. About a month ago one of the local wholesaler had a bunch of nice 6" specimens. I sure the local shops should have them.
Yah, blues and blacks are the same thing, just the baby is often called a black and when they change colors as they get larger sometimes they are called blue....however, most people now-a-days seem to call them black arrowanas.
Monster tends to have them and they are pretty nice looking over there as well, healthy and all.