![]() | Jumping Spider - Thiodina Sylvana Family Salticidae - Jumping Spiders. Also commonly called daring jumping spider. Live adult male jumping spider photographed at Castle Rock State Park in northern Illinois. Spider Index | Spider Main | Funnel Web | Orb Web | Nursery Web | Cobweb | Insects |
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This is a large male jumping spider at 10mm. He was out hunting for prey and females in the leaf-litter on the forest floor at Castle Rock State Park in Illinois, along the banks of the Rock River. I was only able to follow him for a short while - as soon as they notice you watching, they almost always become surreptitious in their movements. Jumping spiders are small to medium in size, stout-bodied and short-legged, with a distinctive eye pattern. The body is rather hairy (pubescent) and frequently brightly colored or iridescent. Some species are antlike in appearance. The jumping spiders forage for their prey in the daytime. They approach prey slowly and, when a short distance away, make a sudden leap onto the unfortunate animal. They are good jumpers and can leap many times their own body length. [3] |

Jumping spider's anatomical points of interest:
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![]() External Spider Anatomy |
| A. Dorsal (top) view B. Front view of face and chelicerae C. Ventral (bottom) view (some legs omitted) [4] |
The male prepares to mate by spinning a small web and depositing a drop of sperm on it from the underside of his abdomen. He then places the tip of his palpus into the sperm, and draws the sperm through the palp's opening into the sperm duct where it is stored. He then goes cruising. If he finds a female, he performs a courtship dance for her, during which she assesses his fitness. If she accepts him, he places his palp against an opening on the underside of her abdomen (her epigynum), and guides it into place by putting a thumb-like projection, the tibial apophysis, into a groove in her epigynum. The palpus then expands, locks in place, and injects the sperm. [3] |
References
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Class Arachnida / Order Araneae: Spiders are the largest group of arachnids. They are easily recognized by their eight legs, and there are few creatures great or small that elicit such irrational fear in mankind. The vast majority of spiders are completely harmless and offer beneficial services, chief of which is keeping the burgeoning insect population in check. I am continually amazed at the resourcefulness of these supremely successful predators. Spider Index | Spider Main | Funnel Web | Orb Web | Nursery Web | Cobweb |