What jumping spiders tell us about color

The science content creator Veritasium highlighted spider research at the University of Cincinnati to explain what we're learning about vision.

UC College of Arts and Sciences Associate Professor Nathan Morehouse shared how human color vision is mediocre compared to that of many other animals, including the jumping spiders he studies in his biology lab.

“Jumping spider eyes are fascinating,” Morehouse said. “Jumping spiders split up things like motion detection and light sensitivity to some eyes and then color vision and fine-detail vision to others.”

In his lab, Morehouse and his students use a process called microspectrophotometry to measure wavelengths of light absorbed by cone cells in the spiders' retinas. While most spiders can see only a few colors on the spectrum between ultraviolet and green, some jumping spiders can see many others, including reds, oranges and yellows. And they do so in surprising ways.

But can the spiders with the cells for color vision actually see those colors?

To find out, Morehouse and his research partners came up with an ingenious system in which they suspended the spiders in front of a screen and gave them a large ball that they held with their eight legs.

When a subtly colored shape floated across the screen in front of them, the spiders who could observe the color moved the ball like a gyroscope to try to follow the moving image.

Researchers think spiders evolved sophisticated color vision, at least in part, to help them avoid toxic prey.

In another experiment, researchers applied gray paint to some termites and red paint to others. On the red-painted termites, they also applied a bitter tasting solution. Spiders released into the termite enclosure quickly learned to avoid the red-colored termites, hunting only the tasty gray-colored ones, which suggested their color vision helped them make the distinction.

Morehouse said there is still much to learn about the fascinating ways we and other animals perceive the world.

“If we owe anything to the world, it's to allow the world to be experienced in the fullness of itself,” Morehouse said. “I think one of the tragedies of extinction is the loss of a totally unique way of experiencing our world, a way of experiencing our world in a way we probably couldn't even imagine.”

Featured image at top: UC Associate Professor Nathan Morehouse sweeps a net to catch jumping spiders in tall grass. Photo/Day’s Edge Productions and Veritasium, Inc.