Using Biiluminescence for Camouflage

Cephlopods can see polarized light, but many of their preditors do not have polarization sensitivity. So a sephlopod could be sitting ther this beautiful octopus, which is the perfect meal in the underwater environment and these fishes are coming around looking for it. At the same time they could send out signals from their skin that have a polarization signal. And so that only a con specific can see the polarization signal and respond to it.