from what i see from my 3 catfish...the tig has a longer snout or the head looks like the shape of a shovelnose catfish and the juruense head is shorter and rounded...i can also see that my jurunese are darker than my tig also.
But if u want to know for sure about the tig at ur lfs, u should take a pic of it and post it for clarifications before you get it.