Theo :

The difference I see most is body shape and color pattern. 1,2 & 3 are shaped like GSF and 4 & 5 are shaped like BG. 1,2,&3 have lines around mouth and are a dark base color while 4 & 5 have no mouth lines and BG base color. It is hard to see as 1 is a strange angle pic. and 5 got fuzzy when enlarged (it is not that dark on sm pic.). Tales show some different shapes and mouth shape and size. 1,2 & 3 have GSF/bass like mouth shape while 4 & 5 ,while large mouthed, still retain BG shaped mouth. I sure don't know the answer if there is one. I hoped someone would or that collectively the discussion would enlighten us all.