Photoreceptor projection reveals heterogeneity of lamina cartridges in the visual system of the Japanese yellow swallowtail butterfly,Papilio xuthus

The compound eye of the butterfly Papilio xuthus is composed of three types of spectrally heterogeneous ommatidia. The ommatidia, which contain nine photoreceptor cells, R1-9, bear four (type I), three (type II), or two (type III) classes of spectral receptors in fixed combinations. The photorece…