Polarization sensitivity in two species of cuttlefish - Sepia plangon (Gray 1849) and Sepia mestus (Gray 1849) - demonstrated with polarized optomotor stimuli.

The existence of polarization sensitivity (PS), most likely resulting from the orthogonal arrangement of microvilli in photoreceptors, has been proposed in cephalopods for some time, although it has rarely been examined behaviourally. Here, we tested the mourning cuttlefish, Sepia plangon, and the reaper cuttlefish, Sepia mestus, for polarization sensitivity using a large-field optomotor stimulus containing polarization contrast. Polaroid filter drums with stripes producing alternating e-vectors were rotated around free-moving animals. Polarized optomotor responses were displayed, and these responses were similar to those performed in response to a black-and-white, vertically-striped drum, whereas no responses were displayed to a plain polarizing control drum producing just a vertical e-vector. This indicates that the animals are able to see the contrast between adjacent stripes in the polarizing drum. To our knowledge, this is the first demonstration of functional polarization sensitivity in cuttlefish.