metamelanopsin

In squid and octopus rhodopsins, acid metarhodopsin (all-trans form) shows light-dependent conversion mainly to the original rhodopsins (11-cis form) at 0°C [16, 17 ], whereas metamelanopsin (all-trans form) is converted to extramelanopsin (7-cis form) in addition to the original melanopsin (11-cis form) [10 ].