..., and specifically in chromatophore organs, indicating the potential for dermal light sensing. In addition to retinal photoreceptors, there are a few well-studied extraocular photoreceptors known in cephalopods. The Japanese flying squid, Todarodes pacificus, has a photoreceptive system in the parolfactory...

...Christopher S. Cobb; Roddy Williamson ABSTRACT Intracellular recordings were made from extraocular photoreceptor cells within isolated epistellar bodies of the lesser or northern octopus Eledone cirrhosa. The cells had resting potentials around −41±5 mV (mean ± S.D., N =60) and showed light-flash...

... neurone is regulated by a spontaneously active excitatory descending interneurone (DI) that is, in turn, inhibited by an uncharacterised extraocular photoreceptor (EOP) system located in the brain. Light directed at the brain results in inhibition of DI activity, which thereby deprives the VPLI neurone...