What Jumping Spiders Teach Us About Color

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Color Vision in Jumping Spiders

Jumping spiders have unique eye structures that allow them to see fine detail and color in a narrow slice of the world.
Different species of jumping spiders have different types of color vision, with some being dichromats, some being trichromats, and some being tetrachromats.
The ability to see red has evolved several times in jumping spiders, suggesting that color vision is an important trait for their survival.
Jumping spiders have expanded color vision compared to other arachnids, with some species being able to see up to 12 colors.

Scientists collect jumping spiders from various locations to study their color vision and identify the species with expanded color vision.
Microspectrophotometry is used to measure the wavelengths of light absorbed by individual cone cells in the spider's retina, determining their color vision capabilities.
Behavioral experiments are conducted to confirm the spiders' ability to see specific colors by showing them moving shapes on a screen and observing their responses.
Transcriptome sequencing and immunohistochemistry are used to identify the genes responsible for expanded color vision and their expression in the spider's eyes.

Jumping spiders have evolved new forms of color vision multiple times independently, with different species acquiring their new visual capabilities in various ways.
Some jumping spiders gained the ability to see red through gene duplication and evolution of the green-sensitive opsin gene, while others developed internal filters to selectively respond to longer wavelengths.
Jumping spiders have evolved expanded color vision by using a filter in front of some of their green-sensitive cone cells, allowing them to see red.

Researchers are investigating the evolutionary advantages of expanded color vision in jumping spiders, particularly in distinguishing between palatable and unpalatable prey.
Experiments with Habronattus pyrrithrix, a jumping spider with good color vision, showed that they can learn to avoid red-painted, bitter-tasting termites and prefer gray-painted, tasty termites.
Spiders with access to color cues performed better, laying eggs sooner and weighing more at the end of the experiment, suggesting a fitness advantage.
Surprisingly, some male jumping spiders display bright red colors during courtship, even though female jumping spiders lack the ability to see red.
Red coloration in male jumping spiders might create a depth illusion, making them appear closer to females and potentially influencing their courtship behavior.
Red coloration in prey items could also be a strategy to deceive jumping spiders, making them appear closer and increasing their chances of escape.

Jumping spiders have unique eye movements that affect their perception of depth, color, and focus.
High-resolution X-ray videos of live spiders' eyes are being collected using the Advanced Photon Source to study these eye movements.
The spiders' retinas can move horizontally, vertically, and twist to change their field of view.
The researchers are investigating how these eye movements impact the spiders' ability to focus, sense depth, and perceive color.
Color vision in jumping spiders may be three-dimensional in a way that is different from human color perception.

The study of jumping spiders' color vision provides insights into the evolution of color vision and the diverse ways it can manifest within a single group of animals.
Color is not an intrinsic property of an object or solely a mental construct but emerges through the co-evolution of eyes and the world they perceive.