When I grew up in Mississippi, there were 5 catagories.....white perch (crappie), bream (which included blue gill, chinkapin, goggle eye), catfish and bass...all others (like gar, choupique, eel, buffalo, etc) fell into "rough fish"....I think most folks call anything in the bream catagory, perch....but they are like you say, in the sunfish family...it's all in how and where you are raised.....but like you say, what difference does it make....