Phototransduction in a Marine Sponge Provides Insights into the Origin of Animal Vision

Highlights • Phototransduction in the sponge Amphimedon queenslandica incorporates both rhabdomeric and ciliary phototransduction signalling pathway components. • Calcium influx, triggered by photodetection, occurs in Amphimedon larval phototaxis. • Genes expressed specifically in photosensory cells in the larval pigment ring support a role for phototransduction signalling pathways in sponges. • Other neural genes are not enriched in Amphimedon photosensory cells; opsins are absent.