"John Pelura, III" wrote in
:

I was wondering if the stripe goes to the tail from birth(hatching) or
does it get there with a little bit of age?

You left out some important info. First, what size are your fish? And
second, does the black line go at all to the tail fin or does it stop
exactly where the fin begins?

Baby SAEs don't always have the line to the fork, but even then it goes at
least 2/3 through the tail.

Liisa