The identification of a new class of photoreceptors in the retina of fruit flies sheds light on the regulation of the pigments of the eye that confer color vision, researchers at New York University’s Center for Developmental Genetics report in a new study appearing in the Public Library of Science’s journal, PloS Biology.

The retinas of most mammals contain two types of photoreceptor cells, the cones for daylight vision and colour vision, and the more sensitive rods for night vision. Nocturnal bats were traditionally believed to possess only rods. Now scientists at the Max Planck Institute for Brain Research in Frankfurt and at The Field Museum for Natural History in Chicago have discovered that nocturnal fruit bats (flying foxes) possess cones in addition to rods.