That may all depend. Many (but not all) hybrids can be identified as being such due to obvious or subtle discrepancies of conformation to a particular species (unless, of course, they're hybrids from two very similar species)....It is almost impossible to know if they are pure...
Due to the variation margin which can exist among red zebras (deep carrot orange to pink-tinted white, and even blue for those originating from Minos Reef in Lake Malawi), body shape and head shape will be the primary indicator. Sometimes they'll look like bulky yellow labs but more orange in color.and a hybrid zebra tends to have a lighter slight yellowish color if it is crossed with a yellow lab which is the most common hybrid right?
That would really depend on the store, in big chains yea you mostly get hybrids in a mixed tank, but in smaller lfs's (or at least the one I'm getting my fish from) they have pure breds in their mixed tanks, you do get an occasional yellow lab with bearding or a red zebra with tiny black blotches (not OB, which mostly disappear as the fish matures), but that's as "bad" as it gets.assorted african tanks are rarely going to contain pure strain species - can still get a nice fish out of them, but most likely a mutt.