Mantis Shrimp See Sixteen Colors

While humans perceive the world through three types of color-receptive cells (for red, green, and blue light), the mantis shrimp boasts the most complex visual system in the animal kingdom. Their eyes are equipped with an incredible 16 types of photoreceptor cells, allowing them to detect wavelengths of light that are completely invisible to us, including deep ultraviolet (UV) light. Furthermore, they can see and process various forms of polarized light, a property of light waves that humans can only detect with special filters. This ability is so advanced they can even distinguish between different types of polarized light, which they may use as a secret communication channel.

Given this complex hardware, scientists initially assumed the mantis shrimp experienced a reality of unimaginable color, a "super-rainbow" far beyond our comprehension. However, behavioral studies revealed a surprising twist. When tested on their ability to distinguish between similar colors, they performed worse than humans. This led to a new theory: their visual system isn't built for nuance, but for speed.

Instead of their brains carefully processing and mixing signals from their many receptors to create a detailed color image, the mantis shrimp may use a simpler form of pattern recognition. Each receptor acts like a specific trigger, instantly identifying a key color without much interpretation. For a creature that relies on split-second decisions to attack prey with lightning-fast strikes in the visually complex environment of a coral (Deals) reef, this instant recognition is a far greater evolutionary advantage than being able to appreciate subtle shades of turquoise.