When if you go buy any Festae you don't know the details of his parents, their parents and so on and so fourth. Naming a line gives the ability to have easy identification from one line to the next, and yes one line can be very different. You can have a line known for its perfect, unbroken barring or do its fiery red males or anything for that matter. The care taken in each generation and being able to pick out and specifically select fish to breed for certain traits can make a huge difference from one line to another!