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Jumping spider

life science Maturity 5-7 Next article →

Jumping spiders belong to the family Salticidae, which is the largest family of spiders.

Phidippus audax male
Phidippus audax male

This group includes almost 700 different genera and about 7,000 described species. Together, they make up 13% of all known spider species. These spiders are famous for having some of the best vision among arthropods. They use this sight for hunting, navigating, and even courtship. Because of their unique eye patterns and body shapes, they are easy to distinguish from other spiders.

Salticidae Male Anterior annotated
Salticidae Male Anterior annotated

The visual system of a jumping spider is incredibly complex. All jumping spiders possess four pairs of eyes, totaling eight eyes. The most important are the anterior median eyes, located in the front middle. These eyes function like small telescopic tubes. They have a corneal lens in the front and a second lens in the back. These lenses focus light onto a four-layered retina, which is a narrow, boomerang-shaped strip. This setup allows for detailed, three-dimensional vision.

Jumping spider vision David Hill
Jumping spider vision David Hill

This vision helps the spider estimate the range and direction of its prey.

To understand how they see depth, we must look at a process called image defocus. Since their eyes are too close together for traditional depth perception, they use their retina layers instead. The two layers closest to the surface contain a UV-sensitive opsin, which is a visual pigment. The two deepest layers contain a green-sensitive opsin. Incoming green light focuses only on the deepest layer. Meanwhile, the other layer receives a fuzzy or defocused image. By measuring this fuzziness, the spider calculates how far away an object is.

Telamonia dimidiata female
Telamonia dimidiata female

This allows them to direct their attacking leaps with great precision.

The other six eyes serve different, vital roles in their survival. The anterior lateral eyes (ALEs) provide a wider forward field of vision. They have high visual acuity and can trigger an instinctive defensive response called a looming response. The posterior lateral eyes (PLEs) act as wide-angle motion detectors. These eyes sense movement from the sides and even from behind. Combined with the other eyes, they provide a near 360° view of the environment. Some species also have posterior median eyes, though these are often vestigial, meaning they have lost their original function.

Jumping spiders move through the world using a unique hydraulic system. Unlike grasshoppers, they do not rely on large leg muscles to leap. Instead, they extend their limbs by altering the pressure of their hemolymph. Hemolymph is the internal body fluid that flows through their system. Most species use their third or fourth pair of legs to perform these agile jumps. Most can jump two or three body lengths. However, the species Colonus puerperus can jump as far as 38 times its own body length.

Unidentified Salticid Jumping with Trailing Dragline
Unidentified Salticid Jumping with Trailing Dragline

Safety is a major priority during these high-energy movements. Before a spider jumps, it attaches a silk filament called a dragline to its surface. This dragline acts as a mechanical aid for braking and stabilization. If a jump fails, the spider can simply climb back up the silk thread.

JumpingSpider hunt macrogiants A
JumpingSpider hunt macrogiants A

Spiders also use silk to build small shelters called "pup tents." They use these tents to sleep at night, molt, and store egg cases. They even use these silken homes to stay safe during the winter.

Their hunting behavior is highly varied and often quite intelligent. Most jumping spiders are diurnal, meaning they hunt during the day. When they spot prey, they swivel their cephalothorax to aim their primary eyes. They may then stalk the prey using a slow, careful approach. Some species, like those in the genus Portia, exhibit complex adaptive behavior. They might take long, circuitous detours to reach a prey item. This ability to navigate complex paths is remarkable for an organism with such a tiny brain.

They are true masters of sight and precision in the natural world.

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🖼️ Images & Media (16)
File:Salticidae Male Anterior annotated.jpg
Salticidae Male Anterior annotated.jpg
Phidippus regius.webm
File:Jumping spider vision David Hill.svg
Jumping spider vision David Hill.svg
File:Telamonia dimidiata female.jpg
Telamonia dimidiata female.jpg
File:Phidippus audax male.jpg
Phidippus audax male.jpg
File:Unidentified Salticid Jumping with Trailing Dragline.jpg
Unidentified Salticid Jumping with...
File:JumpingSpider hunt macrogiants A.jpg
JumpingSpider hunt macrogiants A.jpg
File:Jumping spider with prey.jpg
Jumping spider with prey.jpg
File:Saitis barbipes signaling.jpg
Saitis barbipes signaling.jpg
File:Amilaps mayana Zookeys.891.38563 Fig 10.jpg
Amilaps mayana Zookeys.891.38563 Fig 10.jpg
File:Asemonea amatola Male.jpg
Asemonea amatola Male.jpg
File:Unidentified Lyssomanes (2).jpg
Unidentified Lyssomanes (2).jpg

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