Visual Spectral Sensitivities of Bioluminescent Deep-sea Crustaceans

The spectral sensitivities of eight species of deep-sea decapod shrimps (Family Oplophoridae) were determined from shipboard measurements of electroretinograms of dark-captured specimens. Notostomus gibbosus and N. elegans are maximally sensitive at 490 nm, and chromatic adaptation experiments indicate that a single visual pigment is present. Peak sensitivities of Acanthephyra smithi and A. curtirostris are at 510 nm, a longer wavelength than expected for such deep-sea dwellers. The four photophore-bearing species, Systellaspis debilis, Janicella spinacauda, Oplophorus spinosus, and O. gracilirostris have sensitivity maxima at 400 and 500 nm, and chromatic adaptation experiments indicate the presence of two visual pigments. This unusual short wavelength sensitivity may provide the basis for congener recognition based on the spectral bandwidth of luminescence.