ELECTROPHYSIOLOGICAL STUDIES ON VISION OF CEPHALOPOD-ERG-DETERMINED SPECTRAL SENSITIVITIES OF CUTTLEFISH

The ERG-determined scotopic spectral sensitivity (S_λ) curve of the intact anesthetized cuttlefish Sepiella maindroni de Rochebrune attains its major peak at 490 nm with no secondary peak.In adaptation to white or colour light of different intensities, both peak and shape of S_λ curve have no change.It is suggested that only one receptor system is present in the retina of cuttlefish, as a result, its colour-discrimination ability appears to be lacking.