how to tell the difference between pbb and pbl

[Darkexodus]

hey guys just brout polypterus bichir to my tank. and need help in identifying it
im new to the bichir business ( kind of new to monsterfishkeepers too)
already have
senegal. albino senegal. endlicheri. endlicheri ash ( thats what the owner of the shop told me ).anessrogi. delhezi. and ornates
this one is new.
is it pbb or bbl
and how to tell the difference between them
and need to know about their growth rate.