ninaB¹ mutants are slow to mate (i.e. increased copulation latency), compared to controls. Unlike controls, ninaB¹ mutants do not decrease copulation latency in the presence of parasitic wasps Leptopilina heterotoma and Leptopilina boulardi.

Homozygous flies lack the prolonged depolarising afterpotential (PDA) in the electroretinogram response. In mosaic flies in which the retinal tissue is homozygous for ninaB¹ but the rest of the animal is ninaB⁺, the electroretinogram response is normal (the PDA is restored).

The deep pseudopupil is not visible in homozygous mutant adults, only a weak shadow is detected in the eye. This phenotype can be rescued by supplementing the flies' diet with all-trans retinal.

Superficially like ninaA in aberrant visual physiology, but all eight photoreceptors in each eye facet affected by ninaB; can be restored to wild-type phenotype by dietary supplement of retinal but not by other retinoids.