Male (left) and female (right) mantis shrimps showing a clear difference in polarizing signals. The photographs on the left are of a male mantis shrimp - - note the 2 eyes, the round balls at the top of the photo. The photographs on the right are of a female and she does not show the same change of color in her front paddles that the male shows when the filter is changed from a vertical orientation (top photos) to a horizontal one (bottom photos). We think this way of communication - only visible to animals that can see polarized light - may be important for sex.
Related Links
Deep Scope: Secret Communication Channels in the Ocean: Polarisation vision