Flies carrying Rab6Q71L.ninaE lack the prolonged depolarising afterpotential of the electroretinogram. R1-R6 photoreceptors in 3 day old flies carrying Rab6Q71L.ninaE show a marked reduction in rhabdomere volume compared to control flies and show an abnormal accumulation of membranes at the base of the rhabdomeres. Some R1-R6 photoreceptors show loosely organised rhabdomeric membranes.