Meeting Abstract
Cephalopods have long been known to visually sense polarized light, yet quantifying polarized patterns from these animals has been lacking due to technical difficulties of polarization imaging underwater. We use a custom-built high definition color polarization camera with vertically stacked color photodetectors that has been engineered to be diver operated under water. We use a modified the computer vision tool, perspective from n points (PnP), to fit a virtual 3D model to the 2D image. Using this 3D model, we model the polarization reflections in virtual space and compare with the measured animal. Reef squid, Sepioteuthis lessoniana and Sepioteuthis sepioidea, show specific patterns of the degree of polarization that are dependent on the solar and viewing angle. Specific angle of polarization patterns were found that are not correlated with the solar position. These polarization patterns may contribute to the unique and intricate schooling patterns found in these squid. We quantify these schooling patterns using a goPro-VLAM tracking technique that is able to measure the body positions of animals in addition to being able to map their environment. The Broadclub Cuttlefish, Sepia latimanus show rapid changes in polarization states in response to the movement of the videographer.
