Jumping Spiders, Salticidae

Salticidae is a family that holds over five thousand species of jumping spiders that can be found throughout the world, including areas with heavy snowfall. Most species prefer to reside in tropical forests, but these spiders can also be found in temperate forests, deserts, and mountainous regions, among other habitats. Although the taxonomic structure of this family is well established, the closest relatives of the family have not yet been identified.

Jumping spiders can range in size between .03 and .8 inches and can be easily distinguished from other species by the shape of the cephalothorax and the distinct pattern of eyes. The front legs of these spiders are typically larger than the back legs, which are stronger than the front legs and used for jumping, and none of the legs hold prominent spines. The faces of jumping spiders are triangular in shape and hold a back row of four eyes, which many suggest are actually non-functional. The front eyes are large and allow these spiders to discern the distance, direction, and other details of potential prey. Males are often brightly colored and may have fringe, hair, and other modifications on their body.

Members of the Salticidae family are typically active during the daytime hours and are able hunters, using an internal hydraulic system to launch themselves as far as three times their own body length. Jumping spiders use their silk to hold onto things while jumping, but they will also use it to create shelters in which they rest and spend the winter and lay eggs in. Their hunting methods vary so much that they can become confusing, but most jumping spiders typically will turn their entire body to face potential prey and inspect it. If the object is considered prey, the spider will walk closer to it, release a line of silk, and then jump into it. Some species follow a straight path when hunting, while others move about branches and other objects before capturing prey.

The general movements of these spiders vary greatly, with some species tending to move constantly, stopping only to look around, and others remaining in one area for longer periods. Preferred food types also vary between species but include ants and other spiders. Some species feed on nectar, and Bagheera kiplingi feeds primarily on nectar.

The reproductive habits of jumping spiders rely heavily on eyesight, which females use to watch potential mates perform a courtship dance. This dance consists of the male jumping in a zig-zag pattern, displaying his brightly colored body. If the female is receptive to the male she will crouch down and remain still until he can climb onto her back and inseminate her.

Image Caption: The courtship display of the male Matarus volans (peacock spider). Credit: KDS444/Wikipedia (CC BY-SA 2.0)