Mutant foraging third instar larvae show no photophobic behaviour in a light avoidance assay, in contrast to wild-type controls.

Some photoreceptor cells develop two rhabdomeres in mutant flies. The mutant rhabdomeres are structurally intact in 3 day old adults.

ninaB³ males initiate courtship as efficiently as wild-type males, both in daylight and in the dark. However, in daylight these males show a reduced courtship vigor index compared to that of control males. In the dark, the ninaB³ males scan for the female by spreading their wings and scanning in a zigzag course, as do wild-type males in this courtship assay, and maintain a courtship vigour comparable to that of wild-type males.

ninaB³ males court decapitated males in daylight with the same courtship vigor index as in the dark (in contrast to wild-type males, which show a significantly reduced courtship vigor index towards decapitated males in daylight compared to in the dark).

The deep pseudopupil is not visible in homozygous mutant adults. This phenotype can be rescued by supplementing the flies' diet with all-trans retinal.