I listened to an incredibly fascinating Radiolab episode on Color and learned about the mighty Mantis Shrimp. It has the most sophisticated visual system in the world, as its eyes contain 16 different types of photoreceptors (12 for color analysis, compared to humanity’s 3 cones). Mantis shrimps can thus see polarized light and 4 colors of uv light, and they may also be able to distinguish up to 100,000 colors (compared to the 10,000 seen by human beings).
Do yourself a favor and listen to the Color Radiolab Podcast.
(image by p@ragon)